Commit Graph

12955 Commits

Author SHA1 Message Date
Jens Axboe c0aac682fa This is the 4.19-rc6 release
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Merge tag 'v4.19-rc6' into for-4.20/block

Merge -rc6 in, for two reasons:

1) Resolve a trivial conflict in the blk-mq-tag.c documentation
2) A few important regression fixes went into upstream directly, so
   they aren't in the 4.20 branch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

* tag 'v4.19-rc6': (780 commits)
  Linux 4.19-rc6
  MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c
  cpufreq: qcom-kryo: Fix section annotations
  perf/core: Add sanity check to deal with pinned event failure
  xen/blkfront: correct purging of persistent grants
  Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
  selftests/powerpc: Fix Makefiles for headers_install change
  blk-mq: I/O and timer unplugs are inverted in blktrace
  dax: Fix deadlock in dax_lock_mapping_entry()
  x86/boot: Fix kexec booting failure in the SEV bit detection code
  bcache: add separate workqueue for journal_write to avoid deadlock
  drm/amd/display: Fix Edid emulation for linux
  drm/amd/display: Fix Vega10 lightup on S3 resume
  drm/amdgpu: Fix vce work queue was not cancelled when suspend
  Revert "drm/panel: Add device_link from panel device to DRM device"
  xen/blkfront: When purging persistent grants, keep them in the buffer
  clocksource/drivers/timer-atmel-pit: Properly handle error cases
  block: fix deadline elevator drain for zoned block devices
  ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge
  drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set
  ...

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-01 08:58:57 -06:00
Matthew Wilcox 3159f943aa xarray: Replace exceptional entries
Introduce xarray value entries and tagged pointers to replace radix
tree exceptional entries.  This is a slight change in encoding to allow
the use of an extra bit (we can now store BITS_PER_LONG - 1 bits in a
value entry).  It is also a change in emphasis; exceptional entries are
intimidating and different.  As the comment explains, you can choose
to store values or pointers in the xarray and they are both first-class
citizens.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
2018-09-29 22:47:49 -04:00
Dennis Zhou (Facebook) 74b7c02a9b blkcg: associate a blkg for pages being evicted by swap
A prior patch in this series added blkg association to bios issued by
cgroups. There are two other paths that we want to attribute work back
to the appropriate cgroup: swap and writeback. Here we modify the way
swap tags bios to include the blkg. Writeback will be tackle in the next
patch.

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:29:09 -06:00
Roman Gushchin 172b06c32b mm: slowly shrink slabs with a relatively small number of objects
9092c71bb7 ("mm: use sc->priority for slab shrink targets") changed the
way that the target slab pressure is calculated and made it
priority-based:

    delta = freeable >> priority;
    delta *= 4;
    do_div(delta, shrinker->seeks);

The problem is that on a default priority (which is 12) no pressure is
applied at all, if the number of potentially reclaimable objects is less
than 4096 (1<<12).

This causes the last objects on slab caches of no longer used cgroups to
(almost) never get reclaimed.  It's obviously a waste of memory.

It can be especially painful, if these stale objects are holding a
reference to a dying cgroup.  Slab LRU lists are reparented on memcg
offlining, but corresponding objects are still holding a reference to the
dying cgroup.  If we don't scan these objects, the dying cgroup can't go
away.  Most likely, the parent cgroup hasn't any directly charged objects,
only remaining objects from dying children cgroups.  So it can easily hold
a reference to hundreds of dying cgroups.

If there are no big spikes in memory pressure, and new memory cgroups are
created and destroyed periodically, this causes the number of dying
cgroups grow steadily, causing a slow-ish and hard-to-detect memory
"leak".  It's not a real leak, as the memory can be eventually reclaimed,
but it could not happen in a real life at all.  I've seen hosts with a
steadily climbing number of dying cgroups, which doesn't show any signs of
a decline in months, despite the host is loaded with a production
workload.

It is an obvious waste of memory, and to prevent it, let's apply a minimal
pressure even on small shrinker lists.  E.g.  if there are freeable
objects, let's scan at least min(freeable, scan_batch) objects.

This fix significantly improves a chance of a dying cgroup to be
reclaimed, and together with some previous patches stops the steady growth
of the dying cgroups number on some of our hosts.

Link: http://lkml.kernel.org/r/20180905230759.12236-1-guro@fb.com
Fixes: 9092c71bb7 ("mm: use sc->priority for slab shrink targets")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-20 22:01:11 +02:00
Joel Fernandes (Google) b45d71fb89 mm: shmem.c: Correctly annotate new inodes for lockdep
Directories and inodes don't necessarily need to be in the same lockdep
class.  For ex, hugetlbfs splits them out too to prevent false positives
in lockdep.  Annotate correctly after new inode creation.  If its a
directory inode, it will be put into a different class.

This should fix a lockdep splat reported by syzbot:

> ======================================================
> WARNING: possible circular locking dependency detected
> 4.18.0-rc8-next-20180810+ #36 Not tainted
> ------------------------------------------------------
> syz-executor900/4483 is trying to acquire lock:
> 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at: inode_lock
> include/linux/fs.h:765 [inline]
> 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at:
> shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602
>
> but task is already holding lock:
> 0000000025208078 (ashmem_mutex){+.+.}, at: ashmem_shrink_scan+0xb4/0x630
> drivers/staging/android/ashmem.c:448
>
> which lock already depends on the new lock.
>
> -> #2 (ashmem_mutex){+.+.}:
>        __mutex_lock_common kernel/locking/mutex.c:925 [inline]
>        __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073
>        mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
>        ashmem_mmap+0x55/0x520 drivers/staging/android/ashmem.c:361
>        call_mmap include/linux/fs.h:1844 [inline]
>        mmap_region+0xf27/0x1c50 mm/mmap.c:1762
>        do_mmap+0xa10/0x1220 mm/mmap.c:1535
>        do_mmap_pgoff include/linux/mm.h:2298 [inline]
>        vm_mmap_pgoff+0x213/0x2c0 mm/util.c:357
>        ksys_mmap_pgoff+0x4da/0x660 mm/mmap.c:1585
>        __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
>        __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline]
>        __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> -> #1 (&mm->mmap_sem){++++}:
>        __might_fault+0x155/0x1e0 mm/memory.c:4568
>        _copy_to_user+0x30/0x110 lib/usercopy.c:25
>        copy_to_user include/linux/uaccess.h:155 [inline]
>        filldir+0x1ea/0x3a0 fs/readdir.c:196
>        dir_emit_dot include/linux/fs.h:3464 [inline]
>        dir_emit_dots include/linux/fs.h:3475 [inline]
>        dcache_readdir+0x13a/0x620 fs/libfs.c:193
>        iterate_dir+0x48b/0x5d0 fs/readdir.c:51
>        __do_sys_getdents fs/readdir.c:231 [inline]
>        __se_sys_getdents fs/readdir.c:212 [inline]
>        __x64_sys_getdents+0x29f/0x510 fs/readdir.c:212
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> -> #0 (&sb->s_type->i_mutex_key#9){++++}:
>        lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
>        down_write+0x8f/0x130 kernel/locking/rwsem.c:70
>        inode_lock include/linux/fs.h:765 [inline]
>        shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602
>        ashmem_shrink_scan+0x236/0x630 drivers/staging/android/ashmem.c:455
>        ashmem_ioctl+0x3ae/0x13a0 drivers/staging/android/ashmem.c:797
>        vfs_ioctl fs/ioctl.c:46 [inline]
>        file_ioctl fs/ioctl.c:501 [inline]
>        do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
>        ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
>        __do_sys_ioctl fs/ioctl.c:709 [inline]
>        __se_sys_ioctl fs/ioctl.c:707 [inline]
>        __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> other info that might help us debug this:
>
> Chain exists of:
>   &sb->s_type->i_mutex_key#9 --> &mm->mmap_sem --> ashmem_mutex
>
>  Possible unsafe locking scenario:
>
>        CPU0                    CPU1
>        ----                    ----
>   lock(ashmem_mutex);
>                                lock(&mm->mmap_sem);
>                                lock(ashmem_mutex);
>   lock(&sb->s_type->i_mutex_key#9);
>
>  *** DEADLOCK ***
>
> 1 lock held by syz-executor900/4483:
>  #0: 0000000025208078 (ashmem_mutex){+.+.}, at:
> ashmem_shrink_scan+0xb4/0x630 drivers/staging/android/ashmem.c:448

Link: http://lkml.kernel.org/r/20180821231835.166639-1-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Suggested-by: NeilBrown <neilb@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-20 22:01:11 +02:00
Pasha Tatashin 889c695d41 mm: disable deferred struct page for 32-bit arches
Deferred struct page init is needed only on systems with large amount of
physical memory to improve boot performance.  32-bit systems do not
benefit from this feature.

Jiri reported a problem where deferred struct pages do not work well with
x86-32:

[    0.035162] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
[    0.035725] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
[    0.036269] Initializing CPU#0
[    0.036513] Initializing HighMem for node 0 (00036ffe:0007ffe0)
[    0.038459] page:f6780000 is uninitialized and poisoned
[    0.038460] raw: ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff
[    0.039509] page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page))
[    0.040038] ------------[ cut here ]------------
[    0.040399] kernel BUG at include/linux/page-flags.h:293!
[    0.040823] invalid opcode: 0000 [#1] SMP PTI
[    0.041166] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc1_pt_jiri #9
[    0.041694] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
[    0.042496] EIP: free_highmem_page+0x64/0x80
[    0.042839] Code: 13 46 d8 c1 e8 18 5d 83 e0 03 8d 04 c0 c1 e0 06 ff 80 ec 5f 44 d8 c3 8d b4 26 00 00 00 00 ba 08 65 28 d8 89 d8 e8 fc 71 02 00 <0f> 0b 8d 76 00 8d bc 27 00 00 00 00 ba d0 b1 26 d8 89 d8 e8 e4 71
[    0.044338] EAX: 0000003c EBX: f6780000 ECX: 00000000 EDX: d856cbe8
[    0.044868] ESI: 0007ffe0 EDI: d838df20 EBP: d838df00 ESP: d838defc
[    0.045372] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00210086
[    0.045913] CR0: 80050033 CR2: 00000000 CR3: 18556000 CR4: 00040690
[    0.046413] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[    0.046913] DR6: fffe0ff0 DR7: 00000400
[    0.047220] Call Trace:
[    0.047419]  add_highpages_with_active_regions+0xbd/0x10d
[    0.047854]  set_highmem_pages_init+0x5b/0x71
[    0.048202]  mem_init+0x2b/0x1e8
[    0.048460]  start_kernel+0x1d2/0x425
[    0.048757]  i386_start_kernel+0x93/0x97
[    0.049073]  startup_32_smp+0x164/0x168
[    0.049379] Modules linked in:
[    0.049626] ---[ end trace 337949378db0abbb ]---

We free highmem pages before their struct pages are initialized:

mem_init()
 set_highmem_pages_init()
  add_highpages_with_active_regions()
   free_highmem_page()
    .. Access uninitialized struct page here..

Because there is no reason to have this feature on 32-bit systems, just
disable it.

Link: http://lkml.kernel.org/r/20180831150506.31246-1-pavel.tatashin@microsoft.com
Fixes: 2e3ca40f03 ("mm: relax deferred struct page requirements")
Signed-off-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Reported-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-20 22:01:11 +02:00
Linus Torvalds 48751b562b overlayfs fixes for 4.19-rc4
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Merge tag 'ovl-fixes-4.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs fixes from Miklos Szeredi:
 "This fixes a regression in the recent file stacking update, reported
  and fixed by Amir Goldstein. The fix is fairly trivial, but involves
  adding a fadvise() f_op and the associated churn in the vfs. As
  discussed on -fsdevel, there are other possible uses for this method,
  than allowing proper stacking for overlays.

  And there's one other fix for a syzkaller detected oops"

* tag 'ovl-fixes-4.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix oopses in ovl_fill_super() failure paths
  ovl: add ovl_fadvise()
  vfs: implement readahead(2) using POSIX_FADV_WILLNEED
  vfs: add the fadvise() file operation
  Documentation/filesystems: update documentation of file_operations
  ovl: fix GPF in swapfile_activate of file from overlayfs over xfs
  ovl: respect FIEMAP_FLAG_SYNC flag
2018-09-13 19:21:40 -10:00
Linus Torvalds 7a9cdebdcc mm: get rid of vmacache_flush_all() entirely
Jann Horn points out that the vmacache_flush_all() function is not only
potentially expensive, it's buggy too.  It also happens to be entirely
unnecessary, because the sequence number overflow case can be avoided by
simply making the sequence number be 64-bit.  That doesn't even grow the
data structures in question, because the other adjacent fields are
already 64-bit.

So simplify the whole thing by just making the sequence number overflow
case go away entirely, which gets rid of all the complications and makes
the code faster too.  Win-win.

[ Oleg Nesterov points out that the VMACACHE_FULL_FLUSHES statistics
  also just goes away entirely with this ]

Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Will Deacon <will.deacon@arm.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-09-13 15:18:04 -10:00
Igor Stoppa 0b59c25f91 mm: percpu: remove unnecessary unlikely()
WARN_ON() already contains an unlikely(), so it's not necessary to
wrap it into another.

Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: zijun_hu <zijun_hu@htc.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Dennis Zhou <dennis@kernel.org>
2018-09-12 21:23:23 -07:00
Eric W. Biederman 079b22dc9b signal: Use SEND_SIG_PRIV not SEND_SIG_FORCED with SIGKILL and SIGSTOP
Now that siginfo is never allocated for SIGKILL and SIGSTOP there is
no difference between SEND_SIG_PRIV and SEND_SIG_FORCED for SIGKILL
and SIGSTOP.  This makes SEND_SIG_FORCED unnecessary and redundant in
the presence of SIGKILL and SIGSTOP.  Therefore change users of
SEND_SIG_FORCED that are sending SIGKILL or SIGSTOP to use
SEND_SIG_PRIV instead.

This removes the last users of SEND_SIG_FORCED.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-09-11 21:19:35 +02:00
Peter Zijlstra 196d9d8bb7 mm/memory: Move mmu_gather and TLB invalidation code into its own file
In preparation for maintaining the mmu_gather code as its own entity,
move the implementation out of memory.c and into its own file.

Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-09-07 15:19:25 +01:00
Linus Torvalds ca16eb342e for-linus-20180906
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Merge tag 'for-linus-20180906' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "Small collection of fixes that should go into this release. This
  contains:

   - Small series that fixes a race between blkcg teardown and writeback
     (Dennis Zhou)

   - Fix disallowing invalid block size settings from the nbd ioctl (me)

   - BFQ fix for a use-after-free on last release of a bfqg (Konstantin
     Khlebnikov)

   - Fix for the "don't warn for flush" fix (Mikulas)"

* tag 'for-linus-20180906' of git://git.kernel.dk/linux-block:
  block: bfq: swap puts in bfqg_and_blkg_put
  block: don't warn when doing fsync on read-only devices
  nbd: don't allow invalid blocksize settings
  blkcg: use tryget logic when associating a blkg with a bio
  blkcg: delay blkg destruction until after writeback has finished
  Revert "blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()"
2018-09-06 14:01:15 -07:00
Dave Jiang 62ec0d8c4f mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
It looks like I missed the PUD path when doing VM_MIXEDMAP removal.
This can be triggered by:
1. Boot with memmap=4G!8G
2. build ndctl with destructive flag on
3. make TESTS=device-dax check

[  +0.000675] kernel BUG at mm/huge_memory.c:824!

Applying the same change that was applied to vmf_insert_pfn_pmd() in the
original patch.

Link: http://lkml.kernel.org/r/153565957352.35524.1005746906902065126.stgit@djiang5-desk3.ch.intel.com
Fixes: e1fb4a0864 ("dax: remove VM_MIXEDMAP for fsdax and device dax")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-09-04 16:45:02 -07:00
Aneesh Kumar K.V 464c7ffbcb mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported.
When scanning for movable pages, filter out Hugetlb pages if hugepage
migration is not supported.  Without this we hit infinte loop in
__offline_pages() where we do

	pfn = scan_movable_pages(start_pfn, end_pfn);
	if (pfn) { /* We have movable pages */
		ret = do_migrate_range(pfn, end_pfn);
		goto repeat;
	}

Fix this by checking hugepage_migration_supported both in
has_unmovable_pages which is the primary backoff mechanism for page
offlining and for consistency reasons also into scan_movable_pages
because it doesn't make any sense to return a pfn to non-migrateable
huge page.

This issue was revealed by, but not caused by 72b39cfc4d ("mm,
memory_hotplug: do not fail offlining too early").

Link: http://lkml.kernel.org/r/20180824063314.21981-1-aneesh.kumar@linux.ibm.com
Fixes: 72b39cfc4d ("mm, memory_hotplug: do not fail offlining too early")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reported-by: Haren Myneni <haren@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-09-04 16:45:02 -07:00
Andrew Morton 04b8e94607 mm/util.c: improve kvfree() kerneldoc
Scooped from an email from Matthew.

Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-09-04 16:45:02 -07:00
Vincent Whitchurch b353756b2b kmemleak: always register debugfs file
If kmemleak built in to the kernel, but is disabled by default, the
debugfs file is never registered.  Because of this, it is not possible
to find out if the kernel is built with kmemleak support by checking for
the presence of this file.  To allow this, always register the file.

After this patch, if the file doesn't exist, kmemleak is not available
in the kernel.  If writing "scan" or any other value than "clear" to
this file results in EBUSY, then kmemleak is available but is disabled
by default and can be activated via the kernel command line.

Catalin: "that's also consistent with a late disabling of kmemleak when
the debugfs entry sticks around."

Link: http://lkml.kernel.org/r/20180824131220.19176-1-vincent.whitchurch@axis.com
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-09-04 16:45:02 -07:00
Tetsuo Handa 79cc81057e mm, oom: fix missing tlb_finish_mmu() in __oom_reap_task_mm().
Commit 93065ac753 ("mm, oom: distinguish blockable mode for mmu
notifiers") has added an ability to skip over vmas with blockable mmu
notifiers. This however didn't call tlb_finish_mmu as it should.

As a result inc_tlb_flush_pending has been called without its pairing
dec_tlb_flush_pending and all callers mm_tlb_flush_pending would flush
even though this is not really needed.  This alone is not harmful and it
seems there shouldn't be any such callers for oom victims at all but
there is no real reason to skip tlb_finish_mmu on early skip either so
call it.

[mhocko@suse.com: new changelog]
Link: http://lkml.kernel.org/r/b752d1d5-81ad-7a35-2394-7870641be51c@i-love.sakura.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-09-04 16:45:02 -07:00
Johannes Weiner 3100dab2aa mm: memcontrol: print proper OOM header when no eligible victim left
When the memcg OOM killer runs out of killable tasks, it currently
prints a WARN with no further OOM context.  This has caused some user
confusion.

Warnings indicate a kernel problem.  In a reported case, however, the
situation was triggered by a nonsensical memcg configuration (hard limit
set to 0).  But without any VM context this wasn't obvious from the
report, and it took some back and forth on the mailing list to identify
what is actually a trivial issue.

Handle this OOM condition like we handle it in the global OOM killer:
dump the full OOM context and tell the user we ran out of tasks.

This way the user can identify misconfigurations easily by themselves
and rectify the problem - without having to go through the hassle of
running into an obscure but unsettling warning, finding the appropriate
kernel mailing list and waiting for a kernel developer to remote-analyze
that the memcg configuration caused this.

If users cannot make sense of why the OOM killer was triggered or why it
failed, they will still report it to the mailing list, we know that from
experience.  So in case there is an actual kernel bug causing this,
kernel developers will very likely hear about it.

Link: http://lkml.kernel.org/r/20180821160406.22578-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-09-04 16:45:02 -07:00
Will Deacon a6d60245d6 asm-generic/tlb: Track which levels of the page tables have been cleared
It is common for architectures with hugepage support to require only a
single TLB invalidation operation per hugepage during unmap(), rather than
iterating through the mapping at a PAGE_SIZE increment. Currently,
however, the level in the page table where the unmap() operation occurs
is not stored in the mmu_gather structure, therefore forcing
architectures to issue additional TLB invalidation operations or to give
up and over-invalidate by e.g. invalidating the entire TLB.

Ideally, we could add an interval rbtree to the mmu_gather structure,
which would allow us to associate the correct mapping granule with the
various sub-mappings within the range being invalidated. However, this
is costly in terms of book-keeping and memory management, so instead we
approximate by keeping track of the page table levels that are cleared
and provide a means to query the smallest granule required for invalidation.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-09-04 11:08:27 +01:00
Jann Horn 9da3f2b740 x86/fault: BUG() when uaccess helpers fault on kernel addresses
There have been multiple kernel vulnerabilities that permitted userspace to
pass completely unchecked pointers through to userspace accessors:

 - the waitid() bug - commit 96ca579a1e ("waitid(): Add missing
   access_ok() checks")
 - the sg/bsg read/write APIs
 - the infiniband read/write APIs

These don't happen all that often, but when they do happen, it is hard to
test for them properly; and it is probably also hard to discover them with
fuzzing. Even when an unmapped kernel address is supplied to such buggy
code, it just returns -EFAULT instead of doing a proper BUG() or at least
WARN().

Try to make such misbehaving code a bit more visible by refusing to do a
fixup in the pagefault handler code when a userspace accessor causes a #PF
on a kernel address and the current context isn't whitelisted.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: dvyukov@google.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20180828201421.157735-7-jannh@google.com
2018-09-03 15:12:09 +02:00
Dennis Zhou (Facebook) 59b57717ff blkcg: delay blkg destruction until after writeback has finished
Currently, blkcg destruction relies on a sequence of events:
  1. Destruction starts. blkcg_css_offline() is called and blkgs
     release their reference to the blkcg. This immediately destroys
     the cgwbs (writeback).
  2. With blkgs giving up their reference, the blkcg ref count should
     become zero and eventually call blkcg_css_free() which finally
     frees the blkcg.

Jiufei Xue reported that there is a race between blkcg_bio_issue_check()
and cgroup_rmdir(). To remedy this, blkg destruction becomes contingent
on the completion of all writeback associated with the blkcg. A count of
the number of cgwbs is maintained and once that goes to zero, blkg
destruction can follow. This should prevent premature blkg destruction
related to writeback.

The new process for blkcg cleanup is as follows:
  1. Destruction starts. blkcg_css_offline() is called which offlines
     writeback. Blkg destruction is delayed on the cgwb_refcnt count to
     avoid punting potentially large amounts of outstanding writeback
     to root while maintaining any ongoing policies. Here, the base
     cgwb_refcnt is put back.
  2. When the cgwb_refcnt becomes zero, blkcg_destroy_blkgs() is called
     and handles destruction of blkgs. This is where the css reference
     held by each blkg is released.
  3. Once the blkcg ref count goes to zero, blkcg_css_free() is called.
     This finally frees the blkg.

It seems in the past blk-throttle didn't do the most understandable
things with taking data from a blkg while associating with current. So,
the simplification and unification of what blk-throttle is doing caused
this.

Fixes: 08e18eab0c ("block: add bi_blkg to the bio for cgroups")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Cc: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-31 14:48:56 -06:00
Amir Goldstein 3d8f761531 vfs: implement readahead(2) using POSIX_FADV_WILLNEED
The implementation of readahead(2) syscall is identical to that of
fadvise64(POSIX_FADV_WILLNEED) with a few exceptions:
1. readahead(2) returns -EINVAL for !mapping->a_ops and fadvise64()
   ignores the request and returns 0.
2. fadvise64() checks for integer overflow corner case
3. fadvise64() calls the optional filesystem fadvise() file operation

Unite the two implementations by calling vfs_fadvise() from readahead(2)
syscall. Check the !mapping->a_ops in readahead(2) syscall to preserve
documented syscall ABI behaviour.

Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: d1d04ef857 ("ovl: stack file ops")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-08-30 20:01:32 +02:00
Amir Goldstein 45cd0faae3 vfs: add the fadvise() file operation
This is going to be used by overlayfs and possibly useful
for other filesystems.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-08-30 17:08:35 +02:00
Mukesh Ojha 13ba17bee1 notifier: Remove notifier header file wherever not used
The conversion of the hotplug notifiers to a state machine left the
notifier.h includes around in some places. Remove them.

Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1535114033-4605-1-git-send-email-mojha@codeaurora.org
2018-08-30 12:56:40 +02:00
Linus Torvalds 2923b27e54 libnvdimm-for-4.19_dax-memory-failure
* memory_failure() gets confused by dev_pagemap backed mappings. The
   recovery code has specific enabling for several possible page states
   that needs new enabling to handle poison in dax mappings. Teach
   memory_failure() about ZONE_DEVICE pages.
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Merge tag 'libnvdimm-for-4.19_dax-memory-failure' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm memory-failure update from Dave Jiang:
 "As it stands, memory_failure() gets thoroughly confused by dev_pagemap
  backed mappings. The recovery code has specific enabling for several
  possible page states and needs new enabling to handle poison in dax
  mappings.

  In order to support reliable reverse mapping of user space addresses:

   1/ Add new locking in the memory_failure() rmap path to prevent races
      that would typically be handled by the page lock.

   2/ Since dev_pagemap pages are hidden from the page allocator and the
      "compound page" accounting machinery, add a mechanism to determine
      the size of the mapping that encompasses a given poisoned pfn.

   3/ Given pmem errors can be repaired, change the speculatively
      accessed poison protection, mce_unmap_kpfn(), to be reversible and
      otherwise allow ongoing access from the kernel.

  A side effect of this enabling is that MADV_HWPOISON becomes usable
  for dax mappings, however the primary motivation is to allow the
  system to survive userspace consumption of hardware-poison via dax.
  Specifically the current behavior is:

     mce: Uncorrected hardware memory error in user-access at af34214200
     {1}[Hardware Error]: It has been corrected by h/w and requires no further action
     mce: [Hardware Error]: Machine check events logged
     {1}[Hardware Error]: event severity: corrected
     Memory failure: 0xaf34214: reserved kernel page still referenced by 1 users
     [..]
     Memory failure: 0xaf34214: recovery action for reserved kernel page: Failed
     mce: Memory error not recovered
     <reboot>

  ...and with these changes:

     Injecting memory failure for pfn 0x20cb00 at process virtual address 0x7f763dd00000
     Memory failure: 0x20cb00: Killing dax-pmd:5421 due to hardware memory corruption
     Memory failure: 0x20cb00: recovery action for dax page: Recovered

  Given all the cross dependencies I propose taking this through
  nvdimm.git with acks from Naoya, x86/core, x86/RAS, and of course dax
  folks"

* tag 'libnvdimm-for-4.19_dax-memory-failure' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm, pmem: Restore page attributes when clearing errors
  x86/memory_failure: Introduce {set, clear}_mce_nospec()
  x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses
  mm, memory_failure: Teach memory_failure() about dev_pagemap pages
  filesystem-dax: Introduce dax_lock_mapping_entry()
  mm, memory_failure: Collect mapping size in collect_procs()
  mm, madvise_inject_error: Let memory_failure() optionally take a page reference
  mm, dev_pagemap: Do not clear ->mapping on final put
  mm, madvise_inject_error: Disable MADV_SOFT_OFFLINE for ZONE_DEVICE pages
  filesystem-dax: Set page->index
  device-dax: Set page->index
  device-dax: Enable page_mapping()
  device-dax: Convert to vmf_insert_mixed and vm_fault_t
2018-08-25 18:43:59 -07:00
Linus Torvalds 1b2de5d039 mm/cow: don't bother write protecting already write-protected pages
This is not normally noticeable, but repeated forks are unnecessarily
expensive because they repeatedly dirty the parent page tables during
the page table copy operation.

It's trivial to just avoid write protecting the page table entry if it
was already not writable.

This patch was inspired by

    https://bugzilla.kernel.org/show_bug.cgi?id=200447

which points to an ancient "waste time re-doing fork" issue in the
presence of lots of signals.

That bug was fixed by Eric Biederman's signal handling series
culminating in commit c3ad2c3b02 ("signal: Don't restart fork when
signals come in"), but the unnecessary work for repeated forks is still
work just fixing, particularly since the fix is trivial.

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-25 13:15:03 -07:00
Linus Torvalds 33e17876ea Merge branch 'akpm' (patches from Andrew)
Merge yet more updates from Andrew Morton:

 - the rest of MM

 - various misc fixes and tweaks

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits)
  mm: Change return type int to vm_fault_t for fault handlers
  lib/fonts: convert comments to utf-8
  s390: ebcdic: convert comments to UTF-8
  treewide: convert ISO_8859-1 text comments to utf-8
  drivers/gpu/drm/gma500/: change return type to vm_fault_t
  docs/core-api: mm-api: add section about GFP flags
  docs/mm: make GFP flags descriptions usable as kernel-doc
  docs/core-api: split memory management API to a separate file
  docs/core-api: move *{str,mem}dup* to "String Manipulation"
  docs/core-api: kill trailing whitespace in kernel-api.rst
  mm/util: add kernel-doc for kvfree
  mm/util: make strndup_user description a kernel-doc comment
  fs/proc/vmcore.c: hide vmcoredd_mmap_dumps() for nommu builds
  treewide: correct "differenciate" and "instanciate" typos
  fs/afs: use new return type vm_fault_t
  drivers/hwtracing/intel_th/msu.c: change return type to vm_fault_t
  mm: soft-offline: close the race against page allocation
  mm: fix race on soft-offlining free huge pages
  namei: allow restricted O_CREAT of FIFOs and regular files
  hfs: prevent crash on exit from failed search
  ...
2018-08-23 19:20:12 -07:00
Souptick Joarder 2b74030354 mm: Change return type int to vm_fault_t for fault handlers
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f422059 ("mm: change return type to vm_fault_t")

The aim is to change the return type of finish_fault() and
handle_mm_fault() to vm_fault_t type.  As part of that clean up return
type of all other recursively called functions have been changed to
vm_fault_t type.

The places from where handle_mm_fault() is getting invoked will be
change to vm_fault_t type but in a separate patch.

vmf_error() is the newly introduce inline function in 4.17-rc6.

[akpm@linux-foundation.org: don't shadow outer local `ret' in __do_huge_pmd_anonymous_page()]
Link: http://lkml.kernel.org/r/20180604171727.GA20279@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 18:48:44 -07:00
Mike Rapoport ff4dc77293 mm/util: add kernel-doc for kvfree
Link: http://lkml.kernel.org/r/1532626360-16650-3-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 18:48:43 -07:00
Mike Rapoport b86181f1ad mm/util: make strndup_user description a kernel-doc comment
Patch series "memory management documentation updates", v3.

Here are several updates to the mm documentation.

Aside from really minor changes in the first three patches, the updates
are:

* move the documentation of kstrdup and friends to "String Manipulation"
  section
* split memory management API into a separate .rst file
* adjust formating of the GFP flags description and include it in the
  reference documentation.

This patch (of 7):

The description of the strndup_user function misses '*' character at the
beginning of the comment to be proper kernel-doc.  Add the missing
character.

Link: http://lkml.kernel.org/r/1532626360-16650-2-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 18:48:43 -07:00
Naoya Horiguchi d4ae9916ea mm: soft-offline: close the race against page allocation
A process can be killed with SIGBUS(BUS_MCEERR_AR) when it tries to
allocate a page that was just freed on the way of soft-offline.  This is
undesirable because soft-offline (which is about corrected error) is
less aggressive than hard-offline (which is about uncorrected error),
and we can make soft-offline fail and keep using the page for good
reason like "system is busy."

Two main changes of this patch are:

- setting migrate type of the target page to MIGRATE_ISOLATE. As done
  in free_unref_page_commit(), this makes kernel bypass pcplist when
  freeing the page. So we can assume that the page is in freelist just
  after put_page() returns,

- setting PG_hwpoison on free page under zone->lock which protects
  freelists, so this allows us to avoid setting PG_hwpoison on a page
  that is decided to be allocated soon.

[akpm@linux-foundation.org: tweak set_hwpoison_free_buddy_page() comment]
Link: http://lkml.kernel.org/r/1531452366-11661-3-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Xishi Qiu <xishi.qiuxishi@alibaba-inc.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <zy.zhengyi@alibaba-inc.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 18:48:43 -07:00
Naoya Horiguchi 6bc9b56433 mm: fix race on soft-offlining free huge pages
Patch series "mm: soft-offline: fix race against page allocation".

Xishi recently reported the issue about race on reusing the target pages
of soft offlining.  Discussion and analysis showed that we need make
sure that setting PG_hwpoison should be done in the right place under
zone->lock for soft offline.  1/2 handles free hugepage's case, and 2/2
hanldes free buddy page's case.

This patch (of 2):

There's a race condition between soft offline and hugetlb_fault which
causes unexpected process killing and/or hugetlb allocation failure.

The process killing is caused by the following flow:

  CPU 0               CPU 1              CPU 2

  soft offline
    get_any_page
    // find the hugetlb is free
                      mmap a hugetlb file
                      page fault
                        ...
                          hugetlb_fault
                            hugetlb_no_page
                              alloc_huge_page
                              // succeed
      soft_offline_free_page
      // set hwpoison flag
                                         mmap the hugetlb file
                                         page fault
                                           ...
                                             hugetlb_fault
                                               hugetlb_no_page
                                                 find_lock_page
                                                   return VM_FAULT_HWPOISON
                                           mm_fault_error
                                             do_sigbus
                                             // kill the process

The hugetlb allocation failure comes from the following flow:

  CPU 0                          CPU 1

                                 mmap a hugetlb file
                                 // reserve all free page but don't fault-in
  soft offline
    get_any_page
    // find the hugetlb is free
      soft_offline_free_page
      // set hwpoison flag
        dissolve_free_huge_page
        // fail because all free hugepages are reserved
                                 page fault
                                   ...
                                     hugetlb_fault
                                       hugetlb_no_page
                                         alloc_huge_page
                                           ...
                                             dequeue_huge_page_node_exact
                                             // ignore hwpoisoned hugepage
                                             // and finally fail due to no-mem

The root cause of this is that current soft-offline code is written based
on an assumption that PageHWPoison flag should be set at first to avoid
accessing the corrupted data.  This makes sense for memory_failure() or
hard offline, but does not for soft offline because soft offline is about
corrected (not uncorrected) error and is safe from data lost.  This patch
changes soft offline semantics where it sets PageHWPoison flag only after
containment of the error page completes successfully.

Link: http://lkml.kernel.org/r/1531452366-11661-2-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Xishi Qiu <xishi.qiuxishi@alibaba-inc.com>
Suggested-by: Xishi Qiu <xishi.qiuxishi@alibaba-inc.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <zy.zhengyi@alibaba-inc.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 18:48:43 -07:00
Nicholas Piggin fd1102f0aa mm: mmu_notifier fix for tlb_end_vma
The generic tlb_end_vma does not call invalidate_range mmu notifier, and
it resets resets the mmu_gather range, which means the notifier won't be
called on part of the range in case of an unmap that spans multiple
vmas.

ARM64 seems to be the only arch I could see that has notifiers and uses
the generic tlb_end_vma.  I have not actually tested it.

[ Catalin and Will point out that ARM64 currently only uses the
  notifiers for KVM, which doesn't use the ->invalidate_range()
  callback right now, so it's a bug, but one that happens to
  not affect them.  So not necessary for stable.  - Linus ]

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 11:55:58 -07:00
Peter Zijlstra d86564a2f0 mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE
Jann reported that x86 was missing required TLB invalidates when he
hit the !*batch slow path in tlb_remove_table().

This is indeed the case; RCU_TABLE_FREE does not provide TLB (cache)
invalidates, the PowerPC-hash where this code originated and the
Sparc-hash where this was subsequently used did not need that. ARM
which later used this put an explicit TLB invalidate in their
__p*_free_tlb() functions, and PowerPC-radix followed that example.

But when we hooked up x86 we failed to consider this. Fix this by
(optionally) hooking tlb_remove_table() into the TLB invalidate code.

NOTE: s390 was also needing something like this and might now
      be able to use the generic code again.

[ Modified to be on top of Nick's cleanups, which simplified this patch
  now that tlb_flush_mmu_tlbonly() really only flushes the TLB - Linus ]

Fixes: 9e52fc2b50 ("x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 11:55:58 -07:00
Peter Zijlstra a6f572084f mm/tlb: Remove tlb_remove_table() non-concurrent condition
Will noted that only checking mm_users is incorrect; we should also
check mm_count in order to cover CPUs that have a lazy reference to
this mm (and could do speculative TLB operations).

If removing this turns out to be a performance issue, we can
re-instate a more complete check, but in tlb_table_flush() eliding the
call_rcu_sched().

Fixes: 2672391169 ("mm, powerpc: move the RCU page-table freeing into generic code")
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rik van Riel <riel@surriel.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 11:55:58 -07:00
Nicholas Piggin db7ddef301 mm: move tlb_table_flush to tlb_flush_mmu_free
There is no need to call this from tlb_flush_mmu_tlbonly, it logically
belongs with tlb_flush_mmu_free.  This makes future fixes simpler.

[ This was originally done to allow code consolidation for the
  mmu_notifier fix, but it also ends up helping simplify the
  HAVE_RCU_TABLE_INVALIDATE fix.    - Linus ]

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 11:53:24 -07:00
Peter Zijlstra 52a288c736 x86/mm/tlb: Revert the recent lazy TLB patches
Revert commits:

  95b0e6357d x86/mm/tlb: Always use lazy TLB mode
  64482aafe5 x86/mm/tlb: Only send page table free TLB flush to lazy TLB CPUs
  ac03158969 x86/mm/tlb: Make lazy TLB mode lazier
  61d0beb579 x86/mm/tlb: Restructure switch_mm_irqs_off()
  2ff6ddf19c x86/mm/tlb: Leave lazy TLB mode at page table free time

In order to simplify the TLB invalidate fixes for x86 and unify the
parts that need backporting.  We'll try again later.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 18:22:04 -07:00
Nick Desaulniers 815f0ddb34 include/linux/compiler*.h: make compiler-*.h mutually exclusive
Commit cafa0010cd ("Raise the minimum required gcc version to 4.6")
recently exposed a brittle part of the build for supporting non-gcc
compilers.

Both Clang and ICC define __GNUC__, __GNUC_MINOR__, and
__GNUC_PATCHLEVEL__ for quick compatibility with code bases that haven't
added compiler specific checks for __clang__ or __INTEL_COMPILER.

This is brittle, as they happened to get compatibility by posing as a
certain version of GCC.  This broke when upgrading the minimal version
of GCC required to build the kernel, to a version above what ICC and
Clang claim to be.

Rather than always including compiler-gcc.h then undefining or
redefining macros in compiler-intel.h or compiler-clang.h, let's
separate out the compiler specific macro definitions into mutually
exclusive headers, do more proper compiler detection, and keep shared
definitions in compiler_types.h.

Fixes: cafa0010cd ("Raise the minimum required gcc version to 4.6")
Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Suggested-by: Eli Friedman <efriedma@codeaurora.org>
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 17:31:34 -07:00
Linus Torvalds cd9b44f907 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - the rest of MM

 - procfs updates

 - various misc things

 - more y2038 fixes

 - get_maintainer updates

 - lib/ updates

 - checkpatch updates

 - various epoll updates

 - autofs updates

 - hfsplus

 - some reiserfs work

 - fatfs updates

 - signal.c cleanups

 - ipc/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (166 commits)
  ipc/util.c: update return value of ipc_getref from int to bool
  ipc/util.c: further variable name cleanups
  ipc: simplify ipc initialization
  ipc: get rid of ids->tables_initialized hack
  lib/rhashtable: guarantee initial hashtable allocation
  lib/rhashtable: simplify bucket_table_alloc()
  ipc: drop ipc_lock()
  ipc/util.c: correct comment in ipc_obtain_object_check
  ipc: rename ipcctl_pre_down_nolock()
  ipc/util.c: use ipc_rcu_putref() for failues in ipc_addid()
  ipc: reorganize initialization of kern_ipc_perm.seq
  ipc: compute kern_ipc_perm.id under the ipc lock
  init/Kconfig: remove EXPERT from CHECKPOINT_RESTORE
  fs/sysv/inode.c: use ktime_get_real_seconds() for superblock stamp
  adfs: use timespec64 for time conversion
  kernel/sysctl.c: fix typos in comments
  drivers/rapidio/devices/rio_mport_cdev.c: remove redundant pointer md
  fork: don't copy inconsistent signal handler state to child
  signal: make get_signal() return bool
  signal: make sigkill_pending() return bool
  ...
2018-08-22 12:34:08 -07:00
Anna-Maria Gleixner 060288a732 bdi: use irqsave variant of refcount_dec_and_lock()
The irqsave variant of refcount_dec_and_lock handles irqsave/restore when
taking/releasing the spin lock.  With this variant the call of
local_irq_save/restore is no longer required.

[bigeasy@linutronix.de: s@atomic_dec_and_lock@refcount_dec_and_lock@g]
Link: http://lkml.kernel.org/r/20180703200141.28415-5-bigeasy@linutronix.de
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:46 -07:00
Sebastian Andrzej Siewior e58dd0de5e bdi: use refcount_t for reference counting instead atomic_t
refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter.  This permits avoiding
accidental refcounter overflows that might lead to use-after-free
situations.

Link: http://lkml.kernel.org/r/20180703200141.28415-4-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:46 -07:00
Dennis Zhou (Facebook) 7e8a6304d5 /proc/meminfo: add percpu populated pages count
Currently, percpu memory only exposes allocation and utilization
information via debugfs.  This more or less is only really useful for
understanding the fragmentation and allocation information at a per-chunk
level with a few global counters.  This is also gated behind a config.
BPF and cgroup, for example, have seen an increase in use causing
increased use of percpu memory.  Let's make it easier for someone to
identify how much memory is being used.

This patch adds the "Percpu" stat to meminfo to more easily look up how
much percpu memory is in use.  This number includes the cost for all
allocated backing pages and not just insight at the per a unit, per chunk
level.  Metadata is excluded.  I think excluding metadata is fair because
the backing memory scales with the numbere of cpus and can quickly
outweigh the metadata.  It also makes this calculation light.

Link: http://lkml.kernel.org/r/20180807184723.74919-1-dennisszhou@gmail.com
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:45 -07:00
Roman Gushchin 3d8b38eb81 mm, oom: introduce memory.oom.group
For some workloads an intervention from the OOM killer can be painful.
Killing a random task can bring the workload into an inconsistent state.

Historically, there are two common solutions for this
problem:
1) enabling panic_on_oom,
2) using a userspace daemon to monitor OOMs and kill
   all outstanding processes.

Both approaches have their downsides: rebooting on each OOM is an obvious
waste of capacity, and handling all in userspace is tricky and requires a
userspace agent, which will monitor all cgroups for OOMs.

In most cases an in-kernel after-OOM cleaning-up mechanism can eliminate
the necessity of enabling panic_on_oom.  Also, it can simplify the cgroup
management for userspace applications.

This commit introduces a new knob for cgroup v2 memory controller:
memory.oom.group.  The knob determines whether the cgroup should be
treated as an indivisible workload by the OOM killer.  If set, all tasks
belonging to the cgroup or to its descendants (if the memory cgroup is not
a leaf cgroup) are killed together or not at all.

To determine which cgroup has to be killed, we do traverse the cgroup
hierarchy from the victim task's cgroup up to the OOMing cgroup (or root)
and looking for the highest-level cgroup with memory.oom.group set.

Tasks with the OOM protection (oom_score_adj set to -1000) are treated as
an exception and are never killed.

This patch doesn't change the OOM victim selection algorithm.

Link: http://lkml.kernel.org/r/20180802003201.817-4-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:45 -07:00
Roman Gushchin 5989ad7b5e mm, oom: refactor oom_kill_process()
Patch series "introduce memory.oom.group", v2.

This is a tiny implementation of cgroup-aware OOM killer, which adds an
ability to kill a cgroup as a single unit and so guarantee the integrity
of the workload.

Although it has only a limited functionality in comparison to what now
resides in the mm tree (it doesn't change the victim task selection
algorithm, doesn't look at memory stas on cgroup level, etc), it's also
much simpler and more straightforward.  So, hopefully, we can avoid having
long debates here, as we had with the full implementation.

As it doesn't prevent any futher development, and implements an useful and
complete feature, it looks as a sane way forward.

This patch (of 2):

oom_kill_process() consists of two logical parts: the first one is
responsible for considering task's children as a potential victim and
printing the debug information.  The second half is responsible for
sending SIGKILL to all tasks sharing the mm struct with the given victim.

This commit splits oom_kill_process() with an intention to re-use the the
second half: __oom_kill_process().

The cgroup-aware OOM killer will kill multiple tasks belonging to the
victim cgroup.  We don't need to print the debug information for the each
task, as well as play with task selection (considering task's children),
so we can't use the existing oom_kill_process().

Link: http://lkml.kernel.org/r/20171130152824.1591-2-guro@fb.com
Link: http://lkml.kernel.org/r/20180802003201.817-3-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:45 -07:00
Oscar Salvador 03e85f9d5f mm/page_alloc: Introduce free_area_init_core_hotplug
Currently, whenever a new node is created/re-used from the memhotplug
path, we call free_area_init_node()->free_area_init_core().  But there is
some code that we do not really need to run when we are coming from such
path.

free_area_init_core() performs the following actions:

1) Initializes pgdat internals, such as spinlock, waitqueues and more.
2) Account # nr_all_pages and # nr_kernel_pages. These values are used later on
   when creating hash tables.
3) Account number of managed_pages per zone, substracting dma_reserved and
   memmap pages.
4) Initializes some fields of the zone structure data
5) Calls init_currently_empty_zone to initialize all the freelists
6) Calls memmap_init to initialize all pages belonging to certain zone

When called from memhotplug path, free_area_init_core() only performs
actions #1 and #4.

Action #2 is pointless as the zones do not have any pages since either the
node was freed, or we are re-using it, eitherway all zones belonging to
this node should have 0 pages.  For the same reason, action #3 results
always in manages_pages being 0.

Action #5 and #6 are performed later on when onlining the pages:
 online_pages()->move_pfn_range_to_zone()->init_currently_empty_zone()
 online_pages()->move_pfn_range_to_zone()->memmap_init_zone()

This patch does two things:

First, moves the node/zone initializtion to their own function, so it
allows us to create a small version of free_area_init_core, where we only
perform:

1) Initialization of pgdat internals, such as spinlock, waitqueues and more
4) Initialization of some fields of the zone structure data

These two functions are: pgdat_init_internals() and zone_init_internals().

The second thing this patch does, is to introduce
free_area_init_core_hotplug(), the memhotplug version of
free_area_init_core():

Currently, we call free_area_init_node() from the memhotplug path.  In
there, we set some pgdat's fields, and call calculate_node_totalpages().
calculate_node_totalpages() calculates the # of pages the node has.

Since the node is either new, or we are re-using it, the zones belonging
to this node should not have any pages, so there is no point to calculate
this now.

Actually, we re-set these values to 0 later on with the calls to:

reset_node_managed_pages()
reset_node_present_pages()

The # of pages per node and the # of pages per zone will be calculated when
onlining the pages:

online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_zone_range()
online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_pgdat_range()

Also, since free_area_init_core/free_area_init_node will now only get called during early init, let us replace
__paginginit with __init, so their code gets freed up.

[osalvador@techadventures.net: fix section usage]
  Link: http://lkml.kernel.org/r/20180731101752.GA473@techadventures.net
[osalvador@suse.de: v6]
  Link: http://lkml.kernel.org/r/20180801122348.21588-6-osalvador@techadventures.net
Link: http://lkml.kernel.org/r/20180730101757.28058-5-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:45 -07:00
Oscar Salvador 0188dc98ad mm/page_alloc: inline function to handle CONFIG_DEFERRED_STRUCT_PAGE_INIT
Let us move the code between CONFIG_DEFERRED_STRUCT_PAGE_INIT to an inline
function.  Not having an ifdef in the function makes the code more
readable.

Link: http://lkml.kernel.org/r/20180730101757.28058-4-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:45 -07:00
Pavel Tatashin 7cc2a9596d mm: remove __paginginit
__paginginit is the same thing as __meminit except for platforms without
sparsemem, there it is defined as __init.

Remove __paginginit and use __meminit.  Use __ref in one single function
that merges __meminit and __init sections: setup_usemap().

Link: http://lkml.kernel.org/r/20180801122348.21588-4-osalvador@techadventures.net
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:45 -07:00
Pavel Tatashin c1093b746c mm: access zone->node via zone_to_nid() and zone_set_nid()
zone->node is configured only when CONFIG_NUMA=y, so it is a good idea to
have inline functions to access this field in order to avoid ifdef's in c
files.

Link: http://lkml.kernel.org/r/20180730101757.28058-3-osalvador@techadventures.net
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:45 -07:00
Oscar Salvador ace1db3976 mm/page_alloc.c: move ifdefery out of free_area_init_core
Patch series "Refactor free_area_init_core and add
free_area_init_core_hotplug", v6.

This patchset does three things:

 1) Clean up/refactor free_area_init_core/free_area_init_node
    by moving the ifdefery out of the functions.
 2) Move the pgdat/zone initialization in free_area_init_core to its
    own function.
 3) Introduce free_area_init_core_hotplug, a small subset of
    free_area_init_core, which is only called from memhotlug code path. In this
    way, we have:

    free_area_init_core: called during early initialization
    free_area_init_core_hotplug: called whenever a new node is allocated/re-used (memhotplug path)

This patch (of 5):

Moving the #ifdefs out of the function makes it easier to follow.

Link: http://lkml.kernel.org/r/20180730101757.28058-2-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:45 -07:00
Shakeel Butt 8de7ecc648 memcg: reduce memcg tree traversals for stats collection
Currently cgroup-v1's memcg_stat_show traverses the memcg tree ~17 times
to collect the stats while cgroup-v2's memory_stat_show traverses the
memcg tree thrice.  On a large machine, a couple thousand memcgs is very
normal and if the churn is high and memcgs stick around during to several
reasons, tens of thousands of nodes in memcg tree can exist.  This patch
has refactored and shared the stat collection code between cgroup-v1 and
cgroup-v2 and has reduced the tree traversal to just one.

I ran a simple benchmark which reads the root_mem_cgroup's stat file
1000 times in the presense of 2500 memcgs on cgroup-v1. The results are:

Without the patch:
$ time ./read-root-stat-1000-times

real    0m1.663s
user    0m0.000s
sys     0m1.660s

With the patch:
$ time ./read-root-stat-1000-times

real    0m0.468s
user    0m0.000s
sys     0m0.467s

Link: http://lkml.kernel.org/r/20180724224635.143944-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Bruce Merry <bmerry@ska.ac.za>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Jiang Biao 1c4c3b99c0 mm: fix page_freeze_refs and page_unfreeze_refs in comments
page_freeze_refs/page_unfreeze_refs have already been relplaced by
page_ref_freeze/page_ref_unfreeze , but they are not modified in the
comments.

Link: http://lkml.kernel.org/r/1532590226-106038-1-git-send-email-jiang.biao2@zte.com.cn
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Kees Cook 8c9a134cae mm: clarify CONFIG_PAGE_POISONING and usage
The Kconfig text for CONFIG_PAGE_POISONING doesn't mention that it has to
be enabled explicitly.  This updates the documentation for that and adds a
note about CONFIG_PAGE_POISONING to the "page_poison" command line docs.
While here, change description of CONFIG_PAGE_POISONING_ZERO too, as it's
not "random" data, but rather the fixed debugging value that would be used
when not zeroing.  Additionally removes a stray "bool" in the Kconfig.

Link: http://lkml.kernel.org/r/20180725223832.GA43733@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Andrew Morton a670468f5e mm: zero out the vma in vma_init()
Rather than in vm_area_alloc().  To ensure that the various oddball
stack-based vmas are in a good state.  Some of the callers were zeroing
them out, others were not.

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Mike Rapoport a3bf6ce366 mm/mempool.c: add missing parameter description
The kernel-doc for mempool_init function is missing the description of the
pool parameter.  Add it.

Link: http://lkml.kernel.org/r/1532336274-26228-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Michal Hocko 431f42fdfd mm/oom_kill.c: clean up oom_reap_task_mm()
Andrew has noticed some inconsistencies in oom_reap_task_mm.  Notably

 - Undocumented return value.

 - comment "failed to reap part..." is misleading - sounds like it's
   referring to something which happened in the past, is in fact
   referring to something which might happen in the future.

 - fails to call trace_finish_task_reaping() in one case

 - code duplication.

 - Increases mmap_sem hold time a little by moving
   trace_finish_task_reaping() inside the locked region.  So sue me ;)

 - Sharing the finish: path means that the trace event won't
   distinguish between the two sources of finishing.

Add a short explanation for the return value and fix the rest by
reorganizing the function a bit to have unified function exit paths.

Link: http://lkml.kernel.org/r/20180724141747.GP28386@dhcp22.suse.cz
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Rodrigo Freire c3b78b11ef mm, oom: describe task memory unit, larger PID pad
The default page memory unit of OOM task dump events might not be
intuitive and potentially misleading for the non-initiated when debugging
OOM events: These are pages and not kBs.  Add a small printk prior to the
task dump informing that the memory units are actually memory _pages_.

Also extends PID field to align on up to 7 characters.
Reference https://lkml.org/lkml/2018/7/3/1201

Link: http://lkml.kernel.org/r/c795eb5129149ed8a6345c273aba167ff1bbd388.1530715938.git.rfreire@redhat.com
Signed-off-by: Rodrigo Freire <rfreire@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Michal Hocko af5679fbc6 mm, oom: remove oom_lock from oom_reaper
oom_reaper used to rely on the oom_lock since e2fe14564d ("oom_reaper:
close race with exiting task").  We do not really need the lock anymore
though.  2129258024 ("mm: oom: let oom_reap_task and exit_mmap run
concurrently") has removed serialization with the exit path based on the
mm reference count and so we do not really rely on the oom_lock anymore.

Tetsuo was arguing that at least MMF_OOM_SKIP should be set under the lock
to prevent from races when the page allocator didn't manage to get the
freed (reaped) memory in __alloc_pages_may_oom but it sees the flag later
on and move on to another victim.  Although this is possible in principle
let's wait for it to actually happen in real life before we make the
locking more complex again.

Therefore remove the oom_lock for oom_reaper paths (both exit_mmap and
oom_reap_task_mm).  The reaper serializes with exit_mmap by mmap_sem +
MMF_OOM_SKIP flag.  There is no synchronization with out_of_memory path
now.

[mhocko@kernel.org: oom_reap_task_mm should return false when __oom_reap_task_mm did]
  Link: http://lkml.kernel.org/r/20180724141747.GP28386@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20180719075922.13784-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: David Rientjes <rientjes@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Michal Hocko 93065ac753 mm, oom: distinguish blockable mode for mmu notifiers
There are several blockable mmu notifiers which might sleep in
mmu_notifier_invalidate_range_start and that is a problem for the
oom_reaper because it needs to guarantee a forward progress so it cannot
depend on any sleepable locks.

Currently we simply back off and mark an oom victim with blockable mmu
notifiers as done after a short sleep.  That can result in selecting a new
oom victim prematurely because the previous one still hasn't torn its
memory down yet.

We can do much better though.  Even if mmu notifiers use sleepable locks
there is no reason to automatically assume those locks are held.  Moreover
majority of notifiers only care about a portion of the address space and
there is absolutely zero reason to fail when we are unmapping an unrelated
range.  Many notifiers do really block and wait for HW which is harder to
handle and we have to bail out though.

This patch handles the low hanging fruit.
__mmu_notifier_invalidate_range_start gets a blockable flag and callbacks
are not allowed to sleep if the flag is set to false.  This is achieved by
using trylock instead of the sleepable lock for most callbacks and
continue as long as we do not block down the call chain.

I think we can improve that even further because there is a common pattern
to do a range lookup first and then do something about that.  The first
part can be done without a sleeping lock in most cases AFAICS.

The oom_reaper end then simply retries if there is at least one notifier
which couldn't make any progress in !blockable mode.  A retry loop is
already implemented to wait for the mmap_sem and this is basically the
same thing.

The simplest way for driver developers to test this code path is to wrap
userspace code which uses these notifiers into a memcg and set the hard
limit to hit the oom.  This can be done e.g.  after the test faults in all
the mmu notifier managed memory and set the hard limit to something really
small.  Then we are looking for a proper process tear down.

[akpm@linux-foundation.org: coding style fixes]
[akpm@linux-foundation.org: minor code simplification]
Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christian König <christian.koenig@amd.com> # AMD notifiers
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx and umem_odp
Reported-by: David Rientjes <rientjes@google.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Huang Ying c2343d2761 mm/swapfile.c: put_swap_page: share more between huge/normal code path
In this patch, locking related code is shared between huge/normal code
path in put_swap_page() to reduce code duplication. The `free_entries == 0`
case is merged into the more general `free_entries != SWAPFILE_CLUSTER`
case, because the new locking method makes it easy.

The added lines is same as the removed lines.  But the code size is
increased when CONFIG_TRANSPARENT_HUGEPAGE=n.

		text	   data	    bss	    dec	    hex	filename
base:	       24123	   2004	    340	  26467	   6763	mm/swapfile.o
unified:       24485	   2004	    340	  26829	   68cd	mm/swapfile.o

Dig on step deeper with `size -A mm/swapfile.o` for base and unified
kernel and compare the result, yields,

  -.text                                17723      0
  +.text                                17835      0
  -.orc_unwind_ip                        1380      0
  +.orc_unwind_ip                        1480      0
  -.orc_unwind                           2070      0
  +.orc_unwind                           2220      0
  -Total                                26686
  +Total                                27048

The total difference is the same.  The text segment difference is much
smaller: 112.  More difference comes from the ORC unwinder segments:
(1480 + 2220) - (1380 + 2070) = 250.  If the frame pointer unwinder is
used, this costs nothing.

Link: http://lkml.kernel.org/r/20180720071845.17920-9-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Huang Ying b32d5f32b9 mm/swapfile.c: add __swap_entry_free_locked()
The part of __swap_entry_free() with lock held is separated into a new
function __swap_entry_free_locked().  Because we want to reuse that
piece of code in some other places.

Just mechanical code refactoring, there is no any functional change in
this function.

Link: http://lkml.kernel.org/r/20180720071845.17920-8-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Huang Ying 5d5e8f1954 mm, swap, get_swap_pages: use entry_size instead of cluster in parameter
As suggested by Matthew Wilcox, it is better to use "int entry_size"
instead of "bool cluster" as parameter to specify whether to operate for
huge or normal swap entries.  Because this improve the flexibility to
support other swap entry size.  And Dave Hansen thinks that this
improves code readability too.

So in this patch, the "bool cluster" parameter of get_swap_pages() is
replaced by "int entry_size".

And nr_swap_entries() trick is used to reduce the binary size when
!CONFIG_TRANSPARENT_HUGE_PAGE.

       text	   data	    bss	    dec	    hex	filename
base  24215	   2028	    340	  26583	   67d7	mm/swapfile.o
head  24123	   2004	    340	  26467	   6763	mm/swapfile.o

Link: http://lkml.kernel.org/r/20180720071845.17920-7-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Huang Ying a448f2d07f mm/swapfile.c: unify normal/huge code path in put_swap_page()
In this patch, the normal/huge code path in put_swap_page() and several
helper functions are unified to avoid duplicated code, bugs, etc.  and
make it easier to review the code.

The removed lines are more than added lines.  And the binary size is
kept exactly same when CONFIG_TRANSPARENT_HUGEPAGE=n.

Link: http://lkml.kernel.org/r/20180720071845.17920-6-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Huang Ying 33ee011e56 mm/swapfile.c: unify normal/huge code path in swap_page_trans_huge_swapped()
As suggested by Dave, we should unify the code path for normal and huge
swap support if possible to avoid duplicated code, bugs, etc.  and make
it easier to review code.

In this patch, the normal/huge code path in
swap_page_trans_huge_swapped() is unified, the added and removed lines
are same.  And the binary size is kept almost same when
CONFIG_TRANSPARENT_HUGEPAGE=n.

		 text	   data	    bss	    dec	    hex	filename
base:		24179	   2028	    340	  26547	   67b3	mm/swapfile.o
unified:	24215	   2028	    340	  26583	   67d7	mm/swapfile.o

Link: http://lkml.kernel.org/r/20180720071845.17920-5-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-and-acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:43 -07:00
Huang Ying afa4711ef1 mm/swapfile.c: use swap_count() in swap_page_trans_huge_swapped()
In swap_page_trans_huge_swapped(), to identify whether there's any page
table mapping for a 4k sized swap entry, "si->swap_map[i] !=
SWAP_HAS_CACHE" is used.  This works correctly now, because all users of
the function will only call it after checking SWAP_HAS_CACHE.  But as
pointed out by Daniel, it is better to use "swap_count(map[i])" here,
because it works for "map[i] == 0" case too.

And this makes the implementation more consistent between normal and
huge swap entry.

Link: http://lkml.kernel.org/r/20180720071845.17920-4-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-and-reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:43 -07:00
Huang Ying fe5266d5d5 mm/swapfile.c: replace some #ifdef with IS_ENABLED()
In mm/swapfile.c, THP (Transparent Huge Page) swap specific code is
enclosed by #ifdef CONFIG_THP_SWAP/#endif to avoid code dilating when
THP isn't enabled.  But #ifdef/#endif in .c file hurt the code
readability, so Dave suggested to use IS_ENABLED(CONFIG_THP_SWAP)
instead and let compiler to do the dirty job for us.  This has potential
to remove some duplicated code too.  From output of `size`,

		text	   data	    bss	    dec	    hex	filename
THP=y:         26269	   2076	    340	  28685	   700d	mm/swapfile.o
ifdef/endif:   24115	   2028	    340	  26483	   6773	mm/swapfile.o
IS_ENABLED:    24179	   2028	    340	  26547	   67b3	mm/swapfile.o

IS_ENABLED() based solution works quite well, almost as good as that of
#ifdef/#endif.  And from the diffstat, the removed lines are more than
added lines.

One #ifdef for split_swap_cluster() is kept.  Because it is a public
function with a stub implementation for CONFIG_THP_SWAP=n in swap.h.

Link: http://lkml.kernel.org/r/20180720071845.17920-3-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-and-acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:43 -07:00
Huang Ying 59d98bf3c2 mm: swap: add comments to lock_cluster_or_swap_info()
Patch series "swap: THP optimizing refactoring", v4.

Now the THP (Transparent Huge Page) swap optimizing is implemented in the
way like below,

  #ifdef CONFIG_THP_SWAP
  huge_function(...)
  {
  }
  #else
  normal_function(...)
  {
  }
  #endif

  general_function(...)
  {
  	if (huge)
  		return thp_function(...);
	else
  		return normal_function(...);
  }

As pointed out by Dave Hansen, this will,

1. Create a new, wholly untested code path for huge page
2. Create two places to patch bugs
3. Are not reusing code when possible

This patchset is to address these problems via merging huge/normal code
path/functions if possible.

One concern is that this may cause code size to dilate when
!CONFIG_TRANSPARENT_HUGEPAGE.  The data shows that most refactoring will
only cause quite slight code size increase.

This patch (of 8):

To improve code readability.

Link: http://lkml.kernel.org/r/20180720071845.17920-2-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-and-acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:43 -07:00
Kirill Tkhai 8df4a44cc4 mm: check shrinker is memcg-aware in register_shrinker_prepared()
There is a sad BUG introduced in patch adding SHRINKER_REGISTERING.
shrinker_idr business is only for memcg-aware shrinkers.  Only such type
of shrinkers have id and they must be finaly installed via idr_replace()
in this function.  For !memcg-aware shrinkers we never initialize
shrinker->id field.

But there are all types of shrinkers passed to idr_replace(), and every
!memcg-aware shrinker with random ID (most probably, its id is 0)
replaces memcg-aware shrinker pointed by the ID in IDR.

This patch fixes the problem.

Link: http://lkml.kernel.org/r/8ff8a793-8211-713a-4ed9-d6e52390c2fc@virtuozzo.com
Fixes: 7e010df53c "mm: use special value SHRINKER_REGISTERING instead of list_empty() check"
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reported-by: <syzbot+d5f648a1bfe15678786b@syzkaller.appspotmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <syzkaller-bugs@googlegroups.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:43 -07:00
Linus Torvalds 0214f46b3a Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull core signal handling updates from Eric Biederman:
 "It was observed that a periodic timer in combination with a
  sufficiently expensive fork could prevent fork from every completing.
  This contains the changes to remove the need for that restart.

  This set of changes is split into several parts:

   - The first part makes PIDTYPE_TGID a proper pid type instead
     something only for very special cases. The part starts using
     PIDTYPE_TGID enough so that in __send_signal where signals are
     actually delivered we know if the signal is being sent to a a group
     of processes or just a single process.

   - With that prep work out of the way the logic in fork is modified so
     that fork logically makes signals received while it is running
     appear to be received after the fork completes"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (22 commits)
  signal: Don't send signals to tasks that don't exist
  signal: Don't restart fork when signals come in.
  fork: Have new threads join on-going signal group stops
  fork: Skip setting TIF_SIGPENDING in ptrace_init_task
  signal: Add calculate_sigpending()
  fork: Unconditionally exit if a fatal signal is pending
  fork: Move and describe why the code examines PIDNS_ADDING
  signal: Push pid type down into complete_signal.
  signal: Push pid type down into __send_signal
  signal: Push pid type down into send_signal
  signal: Pass pid type into do_send_sig_info
  signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task
  signal: Pass pid type into group_send_sig_info
  signal: Pass pid and pid type into send_sigqueue
  posix-timers: Noralize good_sigevent
  signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
  pid: Implement PIDTYPE_TGID
  pids: Move the pgrp and session pid pointers from task_struct to signal_struct
  kvm: Don't open code task_pid in kvm_vcpu_ioctl
  pids: Compute task_tgid using signal->leader_pid
  ...
2018-08-21 13:47:29 -07:00
Colin Ian King 1e92641929 mm/hmm.c: remove unused variables align_start and align_end
Variables align_start and align_end are being assigned but are never
used hence they are redundant and can be removed.

Cleans up clang warnings:
  warning: variable 'align_start' set but not used [-Wunused-but-set-variable]
  warning: variable 'align_size' set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/20180714161124.3923-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:33 -07:00
David Rientjes ddbf369c0a mm, vmacache: hash addresses based on pmd
When perf profiling a wide variety of different workloads, it was found
that vmacache_find() had higher than expected cost: up to 0.08% of cpu
utilization in some cases.  This was found to rival other core VM
functions such as alloc_pages_vma() with thp enabled and default
mempolicy, and the conditionals in __get_vma_policy().

VMACACHE_HASH() determines which of the four per-task_struct slots a vma
is cached for a particular address.  This currently depends on the pfn,
so pfn 5212 occupies a different vmacache slot than its neighboring pfn
5213.

vmacache_find() iterates through all four of current's vmacache slots
when looking up an address.  Hashing based on pfn, an address has
~1/VMACACHE_SIZE chance of being cached in the first vmacache slot, or
about 25%, *if* the vma is cached.

This patch hashes an address by its pmd instead of pte to optimize for
workloads with good spatial locality.  This results in a higher
probability of vmas being cached in the first slot that is checked:
normally ~70% on the same workloads instead of 25%.

[rientjes@google.com: various updates]
  Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1807231532290.109445@chino.kir.corp.google.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1807091749150.114630@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Sebastian Andrzej Siewior 6b51e88199 mm/list_lru: introduce list_lru_shrink_walk_irq()
Provide list_lru_shrink_walk_irq() and let it behave like
list_lru_walk_one() except that it locks the spinlock with
spin_lock_irq().  This is used by scan_shadow_nodes() because its lock
nests within the i_pages lock which is acquired with IRQ.  This change
allows to use proper locking promitives instead hand crafted
lock_irq_disable() plus spin_lock().

There is no EXPORT_SYMBOL provided because the current user is in-kernel
only.

Add list_lru_shrink_walk_irq() which acquires the spinlock with the
proper locking primitives.

Link: http://lkml.kernel.org/r/20180716111921.5365-5-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Sebastian Andrzej Siewior 6e018968f8 mm/list_lru.c: pass struct list_lru_node* as an argument to __list_lru_walk_one()
__list_lru_walk_one() is invoked with struct list_lru *lru, int nid as
the first two argument.  Those two are only used to retrieve struct
list_lru_node.  Since this is already done by the caller of the function
for the locking, we can pass struct list_lru_node* directly and avoid
the dance around it.

Link: http://lkml.kernel.org/r/20180716111921.5365-4-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Sebastian Andrzej Siewior 6cfe57a96b mm/list_lru.c: move locking from __list_lru_walk_one() to its caller
Move the locking inside __list_lru_walk_one() to its caller.  This is a
preparation step in order to introduce list_lru_walk_one_irq() which
does spin_lock_irq() instead of spin_lock() for the locking.

Link: http://lkml.kernel.org/r/20180716111921.5365-3-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Sebastian Andrzej Siewior 87a5ffc163 mm/list_lru.c: use list_lru_walk_one() in list_lru_walk_node()
Patch series "mm/list_lru: Add list_lru_shrink_walk_irq() and a user".

This series removes the local_irq_disable() around
list_lru_shrink_walk() (as used by mm/workingset) by adding
list_lru_shrink_walk_irq().

Vladimir Davydov preferred this over `irq' argument which I added to
struct list_lru.

The initial post (of this series) received a Reviewed-by tag by Vladimir
Davydov which I added to each patch of the series.  The series applies
on top of akpm's tree which has Kirill's shrink_slab series and does not
clash with it (akpm asked me to wait a week or so and repost it then).

I tested the code paths by triggering the OOM-killer via memory over
commit and lockdep did not complain (nor did I see any warnings).

This patch (of 4):

list_lru_walk_node() invokes __list_lru_walk_one() with -1 as the
memcg_idx parameter.  The same can be achieved by list_lru_walk_one() and
passing NULL as memcg argument which then gets converted into -1.  This is
a preparation step when the spin_lock() function is lifted to the caller
of __list_lru_walk_one().  Invoke list_lru_walk_one() instead
__list_lru_walk_one() when possible.

Link: http://lkml.kernel.org/r/20180716111921.5365-2-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Huang Ying 14fef28414 mm, swap: make CONFIG_THP_SWAP depend on CONFIG_SWAP
CONFIG_THP_SWAP should depend on CONFIG_SWAP, because it's unreasonable
to optimize swapping for THP (Transparent Huge Page) without basic
swapping support.

In original code, when CONFIG_SWAP=n and CONFIG_THP_SWAP=y,
split_swap_cluster() will not be built because it is in swapfile.c, but
it will be called in huge_memory.c.  This doesn't trigger a build error
in practice because the call site is enclosed by PageSwapCache(), which
is defined to be constant 0 when CONFIG_SWAP=n.  But this is fragile and
should be fixed.

The comments are fixed too to reflect the latest progress.

Link: http://lkml.kernel.org/r/20180713021228.439-1-ying.huang@intel.com
Fixes: 38d8b4e6bd ("mm, THP, swap: delay splitting THP during swap out")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Pavel Tatashin 2a3cb8baef mm/sparse: delete old sparse_init and enable new one
Rename new_sparse_init() to sparse_init() which enables it.  Delete old
sparse_init() and all the code that became obsolete with.

[pasha.tatashin@oracle.com: remove unused sparse_mem_maps_populate_node()]
  Link: http://lkml.kernel.org/r/20180716174447.14529-6-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20180712203730.8703-6-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Tested-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Pavel Tatashin 85c77f7913 mm/sparse: add new sparse_init_nid() and sparse_init()
sparse_init() requires to temporary allocate two large buffers: usemap_map
and map_map.  Baoquan He has identified that these buffers are so large
that Linux is not bootable on small memory machines, such as a kdump boot.
The buffers are especially large when CONFIG_X86_5LEVEL is set, as they
are scaled to the maximum physical memory size.

Baoquan provided a fix, which reduces these sizes of these buffers, but it
is much better to get rid of them entirely.

Add a new way to initialize sparse memory: sparse_init_nid(), which only
operates within one memory node, and thus allocates memory either in large
contiguous block or allocates section by section.  This eliminates the
need for use of temporary buffers.

For simplified bisecting and review temporarly call sparse_init()
new_sparse_init(), the new interface is going to be enabled as well as old
code removed in the next patch.

Link: http://lkml.kernel.org/r/20180712203730.8703-5-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Pavel Tatashin afda57bc13 mm/sparse: move buffer init/fini to the common place
Now that both variants of sparse memory use the same buffers to populate
memory map, we can move sparse_buffer_init()/sparse_buffer_fini() to the
common place.

Link: http://lkml.kernel.org/r/20180712203730.8703-4-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Tested-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Pavel Tatashin e131c06b14 mm/sparse: use the new sparse buffer functions in non-vmemmap
non-vmemmap sparse also allocated large contiguous chunk of memory, and if
fails falls back to smaller allocations.  Use the same functions to
allocate buffer as the vmemmap-sparse

Link: http://lkml.kernel.org/r/20180712203730.8703-3-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Pavel Tatashin 35fd1eb1e8 mm/sparse: abstract sparse buffer allocations
Patch series "sparse_init rewrite", v6.

In sparse_init() we allocate two large buffers to temporary hold usemap
and memmap for the whole machine.  However, we can avoid doing that if
we changed sparse_init() to operated on per-node bases instead of doing
it on the whole machine beforehand.

As shown by Baoquan
  http://lkml.kernel.org/r/20180628062857.29658-1-bhe@redhat.com

The buffers are large enough to cause machine stop to boot on small
memory systems.

Another benefit of these changes is that they also obsolete
CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER.

This patch (of 5):

When struct pages are allocated for sparse-vmemmap VA layout, we first try
to allocate one large buffer, and than if that fails allocate struct pages
for each section as we go.

The code that allocates buffer is uses global variables and is spread
across several call sites.

Cleanup the code by introducing three functions to handle the global
buffer:

sparse_buffer_init()	initialize the buffer
sparse_buffer_fini()	free the remaining part of the buffer
sparse_buffer_alloc()	alloc from the buffer, and if buffer is empty
return NULL

Define these functions in sparse.c instead of sparse-vmemmap.c because
later we will use them for non-vmemmap sparse allocations as well.

[akpm@linux-foundation.org: use PTR_ALIGN()]
[akpm@linux-foundation.org: s/BUG_ON/WARN_ON/]
Link: http://lkml.kernel.org/r/20180712203730.8703-2-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Cannon Matthews 330d6e489a mm/hugetlb.c: don't zero 1GiB bootmem pages
When using 1GiB pages during early boot, use the new
memblock_virt_alloc_try_nid_raw() to allocate memory without zeroing it.
Zeroing out hundreds or thousands of GiB in a single core memset() call
is very slow, and can make early boot last upwards of 20-30 minutes on
multi TiB machines.

The memory does not need to be zero'd as the hugetlb pages are always
zero'd on page fault.

Tested: Booted with ~3800 1G pages, and it booted successfully in
roughly the same amount of time as with 0, as opposed to the 25+ minutes
it would take before.

Link: http://lkml.kernel.org/r/20180711213313.92481-1-cannonmatthews@google.com
Signed-off-by: Cannon Matthews <cannonmatthews@google.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: David Matlack <dmatlack@google.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Aaron Lu d8a759b570 mm, page_alloc: double zone's batchsize
To improve page allocator's performance for order-0 pages, each CPU has
a Per-CPU-Pageset(PCP) per zone.  Whenever an order-0 page is needed,
PCP will be checked first before asking pages from Buddy.  When PCP is
used up, a batch of pages will be fetched from Buddy to improve
performance and the size of batch can affect performance.

zone's batch size gets doubled last time by commit ba56e91c9401("mm:
page_alloc: increase size of per-cpu-pages") over ten years ago.  Since
then, CPU has envolved a lot and CPU's cache sizes also increased.

Dave Hansen is concerned the current batch size doesn't fit well with
modern hardware and suggested me to do two things: first, use a page
allocator intensive benchmark, e.g.  will-it-scale/page_fault1 to find
out how performance changes with different batch sizes on various
machines and then choose a new default batch size; second, see how this
new batch size work with other workloads.

In the first test, we saw performance gains on high-core-count systems
and little to no effect on older systems with more modest core counts.
In this phase's test data, two candidates: 63 and 127 are chosen.

In the second step, ebizzy, oltp, kbuild, pigz, netperf, vm-scalability
and more will-it-scale sub-tests are tested to see how these two
candidates work with these workloads and decides a new default according
to their results.

Most test results are flat.  will-it-scale/page_fault2 process mode has
10%-18% performance increase on 4-sockets Skylake and Broadwell.
vm-scalability/lru-file-mmap-read has 17%-47% performance increase for
4-sockets servers while for 2-sockets servers, it caused 3%-8% performance
drop.  Further analysis showed that, with a larger pcp->batch and thus
larger pcp->high(the relationship of pcp->high=6 * pcp->batch is
maintained in this patch), zone lock contention shifted to LRU add side
lock contention and that caused performance drop.  This performance drop
might be mitigated by others' work on optimizing LRU lock.

Another downside of increasing pcp->batch is, when PCP is used up and need
to fetch a batch of pages from Buddy, since batch is increased, that time
can be longer than before.  My understanding is, this doesn't affect
slowpath where direct reclaim and compaction dominates.  For fastpath,
throughput is a win(according to will-it-scale/page_fault1) but worst
latency can be larger now.

Overall, I think double the batch size from 31 to 63 is relatively safe
and provide good performance boost for high-core-count systems.

The two phase's test results are listed below(all tests are done with THP
disabled).

Phase one(will-it-scale/page_fault1) test results:

Skylake-EX: increased batch size has a good effect on zone->lock
contention, though LRU contention will rise at the same time and
limited the final performance increase.

batch   score     change   zone_contention   lru_contention   total_contention
 31   15345900    +0.00%       64%                 8%           72%
 53   17903847   +16.67%       32%                38%           70%
 63   17992886   +17.25%       24%                45%           69%
 73   18022825   +17.44%       10%                61%           71%
119   18023401   +17.45%        4%                66%           70%
127   18029012   +17.48%        3%                66%           69%
137   18036075   +17.53%        4%                66%           70%
165   18035964   +17.53%        2%                67%           69%
188   18101105   +17.95%        2%                67%           69%
223   18130951   +18.15%        2%                67%           69%
255   18118898   +18.07%        2%                67%           69%
267   18101559   +17.96%        2%                67%           69%
299   18160468   +18.34%        2%                68%           70%
320   18139845   +18.21%        2%                67%           69%
393   18160869   +18.34%        2%                68%           70%
424   18170999   +18.41%        2%                68%           70%
458   18144868   +18.24%        2%                68%           70%
467   18142366   +18.22%        2%                68%           70%
498   18154549   +18.30%        1%                68%           69%
511   18134525   +18.17%        1%                69%           70%

Broadwell-EX: similar pattern as Skylake-EX.

batch   score     change   zone_contention   lru_contention   total_contention
 31   16703983    +0.00%       67%                 7%           74%
 53   18195393    +8.93%       43%                28%           71%
 63   18288885    +9.49%       38%                33%           71%
 73   18344329    +9.82%       35%                37%           72%
119   18535529   +10.96%       24%                46%           70%
127   18513596   +10.83%       23%                48%           71%
137   18514327   +10.84%       23%                48%           71%
165   18511840   +10.82%       22%                49%           71%
188   18593478   +11.31%       17%                53%           70%
223   18601667   +11.36%       17%                52%           69%
255   18774825   +12.40%       12%                58%           70%
267   18754781   +12.28%        9%                60%           69%
299   18892265   +13.10%        7%                63%           70%
320   18873812   +12.99%        8%                62%           70%
393   18891174   +13.09%        6%                64%           70%
424   18975108   +13.60%        6%                64%           70%
458   18932364   +13.34%        8%                62%           70%
467   18960891   +13.51%        5%                65%           70%
498   18944526   +13.41%        5%                64%           69%
511   18960839   +13.51%        5%                64%           69%

Skylake-EP: although increased batch reduced zone->lock contention, but
the effect is not as good as EX: zone->lock contention is still as high as
20% with a very high batch value instead of 1% on Skylake-EX or 5% on
Broadwell-EX.  Also, total_contention actually decreased with a higher
batch but that doesn't translate to performance increase.

batch   score    change   zone_contention   lru_contention   total_contention
 31   9554867    +0.00%       66%                 3%           69%
 53   9855486    +3.15%       63%                 3%           66%
 63   9980145    +4.45%       62%                 4%           66%
 73   10092774   +5.63%       62%                 5%           67%
119   10310061   +7.90%       45%                19%           64%
127   10342019   +8.24%       42%                19%           61%
137   10358182   +8.41%       42%                21%           63%
165   10397060   +8.81%       37%                24%           61%
188   10341808   +8.24%       34%                26%           60%
223   10349135   +8.31%       31%                27%           58%
255   10327189   +8.08%       28%                29%           57%
267   10344204   +8.26%       27%                29%           56%
299   10325043   +8.06%       25%                30%           55%
320   10310325   +7.91%       25%                31%           56%
393   10293274   +7.73%       21%                31%           52%
424   10311099   +7.91%       21%                32%           53%
458   10321375   +8.02%       21%                32%           53%
467   10303881   +7.84%       21%                32%           53%
498   10332462   +8.14%       20%                33%           53%
511   10325016   +8.06%       20%                32%           52%

Broadwell-EP: zone->lock and lru lock had an agreement to make sure
performance doesn't increase and they successfully managed to keep total
contention at 70%.

batch   score    change   zone_contention   lru_contention   total_contention
 31   10121178   +0.00%       19%                50%           69%
 53   10142366   +0.21%        6%                63%           69%
 63   10117984   -0.03%       11%                58%           69%
 73   10123330   +0.02%        7%                63%           70%
119   10108791   -0.12%        2%                67%           69%
127   10166074   +0.44%        3%                66%           69%
137   10141574   +0.20%        3%                66%           69%
165   10154499   +0.33%        2%                68%           70%
188   10124921   +0.04%        2%                67%           69%
223   10137399   +0.16%        2%                67%           69%
255   10143289   +0.22%        0%                68%           68%
267   10123535   +0.02%        1%                68%           69%
299   10140952   +0.20%        0%                68%           68%
320   10163170   +0.41%        0%                68%           68%
393   10000633   -1.19%        0%                69%           69%
424   10087998   -0.33%        0%                69%           69%
458   10187116   +0.65%        0%                69%           69%
467   10146790   +0.25%        0%                69%           69%
498   10197958   +0.76%        0%                69%           69%
511   10152326   +0.31%        0%                69%           69%

Haswell-EP: similar to Broadwell-EP.

batch   score   change   zone_contention   lru_contention   total_contention
 31   10442205   +0.00%       14%                48%           62%
 53   10442255   +0.00%        5%                57%           62%
 63   10452059   +0.09%        6%                57%           63%
 73   10482349   +0.38%        5%                59%           64%
119   10454644   +0.12%        3%                60%           63%
127   10431514   -0.10%        3%                59%           62%
137   10423785   -0.18%        3%                60%           63%
165   10481216   +0.37%        2%                61%           63%
188   10448755   +0.06%        2%                61%           63%
223   10467144   +0.24%        2%                61%           63%
255   10480215   +0.36%        2%                61%           63%
267   10484279   +0.40%        2%                61%           63%
299   10466450   +0.23%        2%                61%           63%
320   10452578   +0.10%        2%                61%           63%
393   10499678   +0.55%        1%                62%           63%
424   10481454   +0.38%        1%                62%           63%
458   10473562   +0.30%        1%                62%           63%
467   10484269   +0.40%        0%                62%           62%
498   10505599   +0.61%        0%                62%           62%
511   10483395   +0.39%        0%                62%           62%

Westmere-EP: contention is pretty small so not interesting.  Note too high
a batch value could hurt performance.

batch   score   change   zone_contention   lru_contention   total_contention
 31   4831523   +0.00%        2%                 3%            5%
 53   4834086   +0.05%        2%                 4%            6%
 63   4834262   +0.06%        2%                 3%            5%
 73   4832851   +0.03%        2%                 4%            6%
119   4830534   -0.02%        1%                 3%            4%
127   4827461   -0.08%        1%                 4%            5%
137   4827459   -0.08%        1%                 3%            4%
165   4820534   -0.23%        0%                 4%            4%
188   4817947   -0.28%        0%                 3%            3%
223   4809671   -0.45%        0%                 3%            3%
255   4802463   -0.60%        0%                 4%            4%
267   4801634   -0.62%        0%                 3%            3%
299   4798047   -0.69%        0%                 3%            3%
320   4793084   -0.80%        0%                 3%            3%
393   4785877   -0.94%        0%                 3%            3%
424   4782911   -1.01%        0%                 3%            3%
458   4779346   -1.08%        0%                 3%            3%
467   4780306   -1.06%        0%                 3%            3%
498   4780589   -1.05%        0%                 3%            3%
511   4773724   -1.20%        0%                 3%            3%

Skylake-Desktop: similar to Westmere-EP, nothing interesting.

batch   score   change   zone_contention   lru_contention   total_contention
 31   3906608   +0.00%        2%                 3%            5%
 53   3940164   +0.86%        2%                 3%            5%
 63   3937289   +0.79%        2%                 3%            5%
 73   3940201   +0.86%        2%                 3%            5%
119   3933240   +0.68%        2%                 3%            5%
127   3930514   +0.61%        2%                 4%            6%
137   3938639   +0.82%        0%                 3%            3%
165   3908755   +0.05%        0%                 3%            3%
188   3905621   -0.03%        0%                 3%            3%
223   3903015   -0.09%        0%                 4%            4%
255   3889480   -0.44%        0%                 3%            3%
267   3891669   -0.38%        0%                 4%            4%
299   3898728   -0.20%        0%                 4%            4%
320   3894547   -0.31%        0%                 4%            4%
393   3875137   -0.81%        0%                 4%            4%
424   3874521   -0.82%        0%                 3%            3%
458   3880432   -0.67%        0%                 4%            4%
467   3888715   -0.46%        0%                 3%            3%
498   3888633   -0.46%        0%                 4%            4%
511   3875305   -0.80%        0%                 5%            5%

Haswell-Desktop: zone->lock is pretty low as other desktops, though lru
contention is higher than other desktops.

batch   score   change   zone_contention   lru_contention   total_contention
 31   3511158   +0.00%        2%                 5%            7%
 53   3555445   +1.26%        2%                 6%            8%
 63   3561082   +1.42%        2%                 6%            8%
 73   3547218   +1.03%        2%                 6%            8%
119   3571319   +1.71%        1%                 7%            8%
127   3549375   +1.09%        0%                 6%            6%
137   3560233   +1.40%        0%                 6%            6%
165   3555176   +1.25%        2%                 6%            8%
188   3551501   +1.15%        0%                 8%            8%
223   3531462   +0.58%        0%                 7%            7%
255   3570400   +1.69%        0%                 7%            7%
267   3532235   +0.60%        1%                 8%            9%
299   3562326   +1.46%        0%                 6%            6%
320   3553569   +1.21%        0%                 8%            8%
393   3539519   +0.81%        0%                 7%            7%
424   3549271   +1.09%        0%                 8%            8%
458   3528885   +0.50%        0%                 8%            8%
467   3526554   +0.44%        0%                 7%            7%
498   3525302   +0.40%        0%                 9%            9%
511   3527556   +0.47%        0%                 8%            8%

Sandybridge-Desktop: the 0% contention isn't accurate but caused by
dropped fractional part. Since multiple contention path's contentions
are all under 1% here, with some arithmetic operations like add, the
final deviation could be as large as 3%.

batch   score   change   zone_contention   lru_contention   total_contention
 31   1744495   +0.00%        0%                 0%            0%
 53   1755341   +0.62%        0%                 0%            0%
 63   1758469   +0.80%        0%                 0%            0%
 73   1759626   +0.87%        0%                 0%            0%
119   1770417   +1.49%        0%                 0%            0%
127   1768252   +1.36%        0%                 0%            0%
137   1767848   +1.34%        0%                 0%            0%
165   1765088   +1.18%        0%                 0%            0%
188   1766918   +1.29%        0%                 0%            0%
223   1767866   +1.34%        0%                 0%            0%
255   1768074   +1.35%        0%                 0%            0%
267   1763187   +1.07%        0%                 0%            0%
299   1765620   +1.21%        0%                 0%            0%
320   1767603   +1.32%        0%                 0%            0%
393   1764612   +1.15%        0%                 0%            0%
424   1758476   +0.80%        0%                 0%            0%
458   1758593   +0.81%        0%                 0%            0%
467   1757915   +0.77%        0%                 0%            0%
498   1753363   +0.51%        0%                 0%            0%
511   1755548   +0.63%        0%                 0%            0%

Phase two test results:
Note: all percent change is against base(batch=31).

ebizzy.throughput (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    2410037±7%     2600451±2% +7.9%     2602878 +8.0%
lkp-bdw-ex1     1493328        1489243    -0.3%     1492145 -0.1%
lkp-skl-2sp2    1329674        1345891    +1.2%     1351056 +1.6%
lkp-bdw-ep2      711511         711511     0.0%      710708 -0.1%
lkp-wsm-ep2       75750          75528    -0.3%       75441 -0.4%
lkp-skl-d01      264126         262791    -0.5%      264113 +0.0%
lkp-hsw-d01      176601         176328    -0.2%      176368 -0.1%
lkp-sb02          98937          98937    +0.0%       99030 +0.1%

kbuild.buildtime (less is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     107.00        107.67  +0.6%        107.11  +0.1%
lkp-bdw-ex1       97.33         97.33  +0.0%         97.42  +0.1%
lkp-skl-2sp2     180.00        179.83  -0.1%        179.83  -0.1%
lkp-bdw-ep2      178.17        179.17  +0.6%        177.50  -0.4%
lkp-wsm-ep2      737.00        738.00  +0.1%        738.00  +0.1%
lkp-skl-d01      642.00        653.00  +1.7%        653.00  +1.7%
lkp-hsw-d01     1310.00       1316.00  +0.5%       1311.00  +0.1%

netperf/TCP_STREAM.Throughput_total_Mbps (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     948790        947144  -0.2%        948333 -0.0%
lkp-bdw-ex1      904224        904366  +0.0%        904926 +0.1%
lkp-skl-2sp2     239731        239607  -0.1%        239565 -0.1%
lk-bdw-ep2       365764        365933  +0.0%        365951 +0.1%
lkp-wsm-ep2       93736         93803  +0.1%         93808 +0.1%
lkp-skl-d01       77314         77303  -0.0%         77375 +0.1%
lkp-hsw-d01       58617         60387  +3.0%         60208 +2.7%
lkp-sb02          29990         30137  +0.5%         30103 +0.4%

oltp.transactions (higer is better)

machine         batch=31      batch=63             batch=127
lkp-bdw-ex1      9073276       9100377     +0.3%    9036344     -0.4%
lkp-skl-2sp2     8898717       8852054     -0.5%    8894459     -0.0%
lkp-bdw-ep2     13426155      13384654     -0.3%   13333637     -0.7%
lkp-hsw-ep2     13146314      13232784     +0.7%   13193163     +0.4%
lkp-wsm-ep2      5035355       5019348     -0.3%    5033418     -0.0%
lkp-skl-d01       418485       4413339     -0.1%    4419039     +0.0%
lkp-hsw-d01      3517817±5%    3396120±3%  -3.5%    3455138±3%  -1.8%

pigz.throughput (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.513e+08     1.507e+08 -0.4%      1.511e+08 -0.2%
lkp-bdw-ex1     2.060e+08     2.052e+08 -0.4%      2.044e+08 -0.8%
lkp-skl-2sp2    8.836e+08     8.845e+08 +0.1%      8.836e+08 -0.0%
lkp-bdw-ep2     8.275e+08     8.464e+08 +2.3%      8.330e+08 +0.7%
lkp-wsm-ep2     2.224e+08     2.221e+08 -0.2%      2.218e+08 -0.3%
lkp-skl-d01     1.177e+08     1.177e+08 -0.0%      1.176e+08 -0.1%
lkp-hsw-d01     1.154e+08     1.154e+08 +0.1%      1.154e+08 -0.0%
lkp-sb02        0.633e+08     0.633e+08 +0.1%      0.633e+08 +0.0%

will-it-scale.malloc1.processes (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1      620181       620484 +0.0%         620240 +0.0%
lkp-bdw-ex1      1403610      1401201 -0.2%        1417900 +1.0%
lkp-skl-2sp2     1288097      1284145 -0.3%        1283907 -0.3%
lkp-bdw-ep2      1427879      1427675 -0.0%        1428266 +0.0%
lkp-hsw-ep2      1362546      1353965 -0.6%        1354759 -0.6%
lkp-wsm-ep2      2099657      2107576 +0.4%        2100226 +0.0%
lkp-skl-d01      1476835      1476358 -0.0%        1474487 -0.2%
lkp-hsw-d01      1308810      1303429 -0.4%        1301299 -0.6%
lkp-sb02          589286       589284 -0.0%         588101 -0.2%

will-it-scale.malloc1.threads (higher is better)
machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     21289         21125     -0.8%      21241     -0.2%
lkp-bdw-ex1      28114         28089     -0.1%      28007     -0.4%
lkp-skl-2sp2     91866         91946     +0.1%      92723     +0.9%
lkp-bdw-ep2      37637         37501     -0.4%      37317     -0.9%
lkp-hsw-ep2      43673         43590     -0.2%      43754     +0.2%
lkp-wsm-ep2      28577         28298     -1.0%      28545     -0.1%
lkp-skl-d01     175277        173343     -1.1%     173082     -1.3%
lkp-hsw-d01     130303        129566     -0.6%     129250     -0.8%
lkp-sb02        113742±3%     116911     +2.8%     116417±3%  +2.4%

will-it-scale.malloc2.processes (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.206e+09     1.206e+09 -0.0%      1.206e+09 +0.0%
lkp-bdw-ex1     1.319e+09     1.319e+09 -0.0%      1.319e+09 +0.0%
lkp-skl-2sp2    8.000e+08     8.021e+08 +0.3%      7.995e+08 -0.1%
lkp-bdw-ep2     6.582e+08     6.634e+08 +0.8%      6.513e+08 -1.1%
lkp-hsw-ep2     6.671e+08     6.669e+08 -0.0%      6.665e+08 -0.1%
lkp-wsm-ep2     1.805e+08     1.806e+08 +0.0%      1.804e+08 -0.1%
lkp-skl-d01     1.611e+08     1.611e+08 -0.0%      1.610e+08 -0.0%
lkp-hsw-d01     1.333e+08     1.332e+08 -0.0%      1.332e+08 -0.0%
lkp-sb02         82485104      82478206 -0.0%       82473546 -0.0%

will-it-scale.malloc2.threads (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.574e+09     1.574e+09 -0.0%      1.574e+09 -0.0%
lkp-bdw-ex1     1.737e+09     1.737e+09 +0.0%      1.737e+09 -0.0%
lkp-skl-2sp2    9.161e+08     9.162e+08 +0.0%      9.181e+08 +0.2%
lkp-bdw-ep2     7.856e+08     8.015e+08 +2.0%      8.113e+08 +3.3%
lkp-hsw-ep2     6.908e+08     6.904e+08 -0.1%      6.907e+08 -0.0%
lkp-wsm-ep2     2.409e+08     2.409e+08 +0.0%      2.409e+08 -0.0%
lkp-skl-d01     1.199e+08     1.199e+08 -0.0%      1.199e+08 -0.0%
lkp-hsw-d01     1.029e+08     1.029e+08 -0.0%      1.029e+08 +0.0%
lkp-sb02         68081213      68061423 -0.0%       68076037 -0.0%

will-it-scale.page_fault2.processes (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    14509125±4%   16472364 +13.5%       17123117 +18.0%
lkp-bdw-ex1     14736381      16196588  +9.9%       16364011 +11.0%
lkp-skl-2sp2     6354925       6435444  +1.3%        6436644  +1.3%
lkp-bdw-ep2      8749584       8834422  +1.0%        8827179  +0.9%
lkp-hsw-ep2      8762591       8845920  +1.0%        8825697  +0.7%
lkp-wsm-ep2      3036083       3030428  -0.2%        3021741  -0.5%
lkp-skl-d01      2307834       2304731  -0.1%        2286142  -0.9%
lkp-hsw-d01      1806237       1800786  -0.3%        1795943  -0.6%
lkp-sb02          842616        837844  -0.6%         833921  -1.0%

will-it-scale.page_fault2.threads

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     1623294       1615132±2% -0.5%     1656777    +2.1%
lkp-bdw-ex1      1995714       2025948    +1.5%     2113753±3% +5.9%
lkp-skl-2sp2     2346708       2415591    +2.9%     2416919    +3.0%
lkp-bdw-ep2      2342564       2344882    +0.1%     2300206    -1.8%
lkp-hsw-ep2      1820658       1831681    +0.6%     1844057    +1.3%
lkp-wsm-ep2      1725482       1733774    +0.5%     1740517    +0.9%
lkp-skl-d01      1832833       1823628    -0.5%     1806489    -1.4%
lkp-hsw-d01      1427913       1427287    -0.0%     1420226    -0.5%
lkp-sb02          750626        748615    -0.3%      746621    -0.5%

will-it-scale.page_fault3.processes (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    24382726      24400317 +0.1%       24668774 +1.2%
lkp-bdw-ex1     35399750      35683124 +0.8%       35829492 +1.2%
lkp-skl-2sp2    28136820      28068248 -0.2%       28147989 +0.0%
lkp-bdw-ep2     37269077      37459490 +0.5%       37373073 +0.3%
lkp-hsw-ep2     36224967      36114085 -0.3%       36104908 -0.3%
lkp-wsm-ep2     16820457      16911005 +0.5%       16968596 +0.9%
lkp-skl-d01      7721138       7725904 +0.1%        7756740 +0.5%
lkp-hsw-d01      7611979       7650928 +0.5%        7651323 +0.5%
lkp-sb02         3781546       3796502 +0.4%        3796827 +0.4%

will-it-scale.page_fault3.threads (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     1865820±3%   1900917±2%  +1.9%     1826245±4%  -2.1%
lkp-bdw-ex1      3094060      3148326     +1.8%     3150036     +1.8%
lkp-skl-2sp2     3952940      3953898     +0.0%     3989360     +0.9%
lkp-bdw-ep2      3420373±3%   3643964     +6.5%     3644910±5%  +6.6%
lkp-hsw-ep2      2609635±2%   2582310±3%  -1.0%     2780459     +6.5%
lkp-wsm-ep2      4395001      4417196     +0.5%     4432499     +0.9%
lkp-skl-d01      5363977      5400003     +0.7%     5411370     +0.9%
lkp-hsw-d01      5274131      5311294     +0.7%     5319359     +0.9%
lkp-sb02         2917314      2913004     -0.1%     2935286     +0.6%

will-it-scale.read1.processes (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    73762279±14%  69322519±10% -6.0%    69349855±13%  -6.0% (result unstable)
lkp-bdw-ex1     1.701e+08     1.704e+08    +0.1%    1.705e+08     +0.2%
lkp-skl-2sp2    63111570      63113953     +0.0%    63836573      +1.1%
lkp-bdw-ep2     79247409      79424610     +0.2%    78012656      -1.6%
lkp-hsw-ep2     67677026      68308800     +0.9%    67539106      -0.2%
lkp-wsm-ep2     13339630      13939817     +4.5%    13766865      +3.2%
lkp-skl-d01     10969487      10972650     +0.0%    no data
lkp-hsw-d01     9857342±2%    10080592±2%  +2.3%    10131560      +2.8%
lkp-sb02        5189076        5197473     +0.2%    5163253       -0.5%

will-it-scale.read1.threads (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    62468045±12%  73666726±7% +17.9%    79553123±12% +27.4% (result unstable)
lkp-bdw-ex1     1.62e+08      1.624e+08    +0.3%    1.614e+08     -0.3%
lkp-skl-2sp2    58319780      59181032     +1.5%    59821353      +2.6%
lkp-bdw-ep2     74057992      75698171     +2.2%    74990869      +1.3%
lkp-hsw-ep2     63672959      63639652     -0.1%    64387051      +1.1%
lkp-wsm-ep2     13489943      13526058     +0.3%    13259032      -1.7%
lkp-skl-d01     10297906      10338796     +0.4%    10407328      +1.1%
lkp-hsw-d01      9636721       9667376     +0.3%     9341147      -3.1%
lkp-sb02         4801938       4804496     +0.1%     4802290      +0.0%

will-it-scale.write1.processes (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.111e+08     1.104e+08±2%  -0.7%   1.122e+08±2%  +1.0%
lkp-bdw-ex1     1.392e+08     1.399e+08     +0.5%   1.397e+08     +0.4%
lkp-skl-2sp2     59369233      58994841     -0.6%    58715168     -1.1%
lkp-bdw-ep2      61820979      CPU throttle          63593123     +2.9%
lkp-hsw-ep2      57897587      57435605     -0.8%    56347450     -2.7%
lkp-wsm-ep2       7814203       7918017±2%  +1.3%     7669068     -1.9%
lkp-skl-d01       8886557       8971422     +1.0%     8818366     -0.8%
lkp-hsw-d01       9171001±5%    9189915     +0.2%     9483909     +3.4%
lkp-sb02          4475406       4475294     -0.0%     4501756     +0.6%

will-it-scale.write1.threads (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.058e+08     1.055e+08±2%  -0.2%   1.065e+08  +0.7%
lkp-bdw-ex1     1.316e+08     1.300e+08     -1.2%   1.308e+08  -0.6%
lkp-skl-2sp2     54492421      56086678     +2.9%    55975657  +2.7%
lkp-bdw-ep2      59360449      59003957     -0.6%    58101262  -2.1%
lkp-hsw-ep2      53346346±2%   52530876     -1.5%    52902487  -0.8%
lkp-wsm-ep2       7774006       7800092±2%  +0.3%     7558833  -2.8%
lkp-skl-d01       8346174       8235695     -1.3%     no data
lkp-hsw-d01       8636244       8655731     +0.2%     8658868  +0.3%
lkp-sb02          4181820       4204107     +0.5%     4182992  +0.0%

vm-scalability.anon-r-rand.throughput (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    11933873±3%   12356544±2%  +3.5%   12188624     +2.1%
lkp-bdw-ex1      7114424±2%    7330949±2%  +3.0%    7392419     +3.9%
lkp-skl-2sp2     6773277±5%    6492332±8%  -4.1%    6543962     -3.4%
lkp-bdw-ep2      7133846±4%    7233508     +1.4%    7013518±3%  -1.7%
lkp-hsw-ep2      4576626       4527098     -1.1%    4551679     -0.5%
lkp-wsm-ep2      2583599       2592492     +0.3%    2588039     +0.2%
lkp-hsw-d01       998199±2%    1028311     +3.0%    1006460±2%  +0.8%
lkp-sb02          570572        567854     -0.5%     568449     -0.4%

vm-scalability.anon-r-rand-mt.throughput (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     1789419       1787830     -0.1%    1788208     -0.1%
lkp-bdw-ex1      3492595±2%    3554966±2%  +1.8%    3558835±3%  +1.9%
lkp-skl-2sp2     3856238±2%    3975403±4%  +3.1%    3994600     +3.6%
lkp-bdw-ep2      3726963±11%   3809292±6%  +2.2%    3871924±4%  +3.9%
lkp-hsw-ep2      2131760±3%    2033578±4%  -4.6%    2130727±6%  -0.0%
lkp-wsm-ep2      2369731       2368384     -0.1%    2370252     +0.0%
lkp-skl-d01      1207128       1206220     -0.1%    1205801     -0.1%
lkp-hsw-d01       964317        992329±2%  +2.9%     992099±2%  +2.9%
lkp-sb02          567137        567346     +0.0%     566144     -0.2%

vm-scalability.lru-file-mmap-read.throughput (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    19560469±6%   23018999     +17.7%   23418800     +19.7%
lkp-bdw-ex1     17769135±14%  26141676±3%  +47.1%   26284723±5%  +47.9%
lkp-skl-2sp2    14056512      13578884      -3.4%   13146214      -6.5%
lkp-bdw-ep2     15336542      14737654      -3.9%   14088159      -8.1%
lkp-hsw-ep2     16275498      15756296      -3.2%   15018090      -7.7%
lkp-wsm-ep2     11272160      11237231      -0.3%   11310047      +0.3%
lkp-skl-d01      7322119       7324569      +0.0%    7184148      -1.9%
lkp-hsw-d01      6449234       6404542      -0.7%    6356141      -1.4%
lkp-sb02         3517943       3520668      +0.1%    3527309      +0.3%

vm-scalability.lru-file-mmap-read-rand.throughput (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     1689052       1697553  +0.5%       1698726  +0.6%
lkp-bdw-ex1      1675246       1699764  +1.5%       1712226  +2.2%
lkp-skl-2sp2     1800533       1799749  -0.0%       1800581  +0.0%
lkp-bdw-ep2      1807422       1807758  +0.0%       1804932  -0.1%
lkp-hsw-ep2      1809807       1808781  -0.1%       1807811  -0.1%
lkp-wsm-ep2      1800198       1802434  +0.1%       1801236  +0.1%
lkp-skl-d01       696689        695537  -0.2%        694106  -0.4%
lkp-hsw-d01       698364        698666  +0.0%        696686  -0.2%
lkp-sb02          258939        258787  -0.1%        258199  -0.3%

Link: http://lkml.kernel.org/r/20180711055855.29072-1-aaron.lu@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Michal Hocko a195d3f5b7 mm/oom_kill.c: document oom_lock
Add comments describing oom_lock's scope.

Requested-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/20180711120121.25635-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Mike Kravetz 40d18ebffb mm/hugetlb: remove gigantic page support for HIGHMEM
This reverts ee8f248d26 ("hugetlb: add phys addr to struct
huge_bootmem_page").

At one time powerpc used this field and supporting code.  However that
was removed with commit 79cc38ded1 ("powerpc/mm/hugetlb: Add support
for reserving gigantic huge pages via kernel command line").

There are no users of this field and supporting code, so remove it.

Link: http://lkml.kernel.org/r/20180711195913.1294-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Cannon Matthews <cannonmatthews@google.com>
Cc: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Michal Hocko 9bfe5ded05 mm, oom: remove sleep from under oom_lock
Tetsuo has pointed out that since 27ae357fa8 ("mm, oom: fix concurrent
munlock and oom reaper unmap, v3") we have a strong synchronization
between the oom_killer and victim's exiting because both have to take
the oom_lock.  Therefore the original heuristic to sleep for a short
time in out_of_memory doesn't serve the original purpose.

Moreover Tetsuo has noticed that the short sleep can be more harmful
than actually useful.  Hammering the system with many processes can lead
to a starvation when the task holding the oom_lock can block for a long
time (minutes) and block any further progress because the oom_reaper
depends on the oom_lock as well.

Drop the short sleep from out_of_memory when we hold the lock.  Keep the
sleep when the trylock fails to throttle the concurrent OOM paths a bit.
This should be solved in a more reasonable way (e.g.  sleep proportional
to the time spent in the active reclaiming etc.) but this is much more
complex thing to achieve.  This is a quick fixup to remove a stale code.

Link: http://lkml.kernel.org/r/20180709074706.30635-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Marek Szyprowski 6518202970 mm/cma: remove unsupported gfp_mask parameter from cma_alloc()
cma_alloc() doesn't really support gfp flags other than __GFP_NOWARN, so
convert gfp_mask parameter to boolean no_warn parameter.

This will help to avoid giving false feeling that this function supports
standard gfp flags and callers can pass __GFP_ZERO to get zeroed buffer,
what has already been an issue: see commit dd65a941f6 ("arm64:
dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag").

Link: http://lkml.kernel.org/r/20180709122019eucas1p2340da484acfcc932537e6014f4fd2c29~-sqTPJKij2939229392eucas1p2j@eucas1p2.samsung.com
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michał Nazarewicz <mina86@mina86.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:32 -07:00
Rik van Riel 50c150f262 Revert "mm: always flush VMA ranges affected by zap_page_range"
There was a bug in Linux that could cause madvise (and mprotect?) system
calls to return to userspace without the TLB having been flushed for all
the pages involved.

This could happen when multiple threads of a process made simultaneous
madvise and/or mprotect calls.

This was noticed in the summer of 2017, at which time two solutions
were created:

  56236a5955 ("mm: refactor TLB gathering API")
  99baac21e4 ("mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem")
and
  4647706ebe ("mm: always flush VMA ranges affected by zap_page_range")

We need only one of these solutions, and the former appears to be a
little more efficient than the latter, so revert that one.

This reverts 4647706ebe ("mm: always flush VMA ranges affected by
zap_page_range")

Link: http://lkml.kernel.org/r/20180706131019.51e3a5f0@imladris.surriel.com
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Baoquan He c98aff6493 mm/sparse: optimize memmap allocation during sparse_init()
In sparse_init(), two temporary pointer arrays, usemap_map and map_map
are allocated with the size of NR_MEM_SECTIONS.  They are used to store
each memory section's usemap and mem map if marked as present.  With the
help of these two arrays, continuous memory chunk is allocated for
usemap and memmap for memory sections on one node.  This avoids too many
memory fragmentations.  Like below diagram, '1' indicates the present
memory section, '0' means absent one.  The number 'n' could be much
smaller than NR_MEM_SECTIONS on most of systems.

  |1|1|1|1|0|0|0|0|1|1|0|0|...|1|0||1|0|...|1||0|1|...|0|
  -------------------------------------------------------
   0 1 2 3         4 5         i   i+1     n-1   n

If we fail to populate the page tables to map one section's memmap, its
->section_mem_map will be cleared finally to indicate that it's not
present.  After use, these two arrays will be released at the end of
sparse_init().

In 4-level paging mode, each array costs 4M which can be ignorable.
While in 5-level paging, they costs 256M each, 512M altogether.  Kdump
kernel Usually only reserves very few memory, e.g 256M.  So, even thouth
they are temporarily allocated, still not acceptable.

In fact, there's no need to allocate them with the size of
NR_MEM_SECTIONS.  Since the ->section_mem_map clearing has been deferred
to the last, the number of present memory sections are kept the same
during sparse_init() until we finally clear out the memory section's
->section_mem_map if its usemap or memmap is not correctly handled.
Thus in the middle whenever for_each_present_section_nr() loop is taken,
the i-th present memory section is always the same one.

Here only allocate usemap_map and map_map with the size of
'nr_present_sections'.  For the i-th present memory section, install its
usemap and memmap to usemap_map[i] and mam_map[i] during allocation.
Then in the last for_each_present_section_nr() loop which clears the
failed memory section's ->section_mem_map, fetch usemap and memmap from
usemap_map[] and map_map[] array and set them into mem_section[]
accordingly.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20180628062857.29658-5-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oscar Salvador <osalvador@techadventures.net>
Cc: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Baoquan He 9258631b33 mm/sparse.c: add a new parameter 'data_unit_size' for alloc_usemap_and_memmap
It's used to pass the size of map data unit into
alloc_usemap_and_memmap, and is preparation for next patch.

Link: http://lkml.kernel.org/r/20180228032657.32385-4-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Pankaj Gupta <pagupta@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Baoquan He 07a34a8c36 mm/sparsemem.c: defer the ms->section_mem_map clearing
In sparse_init(), if CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER=y, system
will allocate one continuous memory chunk for mem maps on one node and
populate the relevant page tables to map memory section one by one.  If
fail to populate for a certain mem section, print warning and its
->section_mem_map will be cleared to cancel the marking of being
present.  Like this, the number of mem sections marked as present could
become less during sparse_init() execution.

Here just defer the ms->section_mem_map clearing if failed to populate
its page tables until the last for_each_present_section_nr() loop.  This
is in preparation for later optimizing the mem map allocation.

[akpm@linux-foundation.org: remove now-unused local `ms', per Oscar]
Link: http://lkml.kernel.org/r/20180228032657.32385-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Baoquan He f2fc10e0b3 mm/sparse.c: add a static variable nr_present_sections
Patch series "mm/sparse: Optimize memmap allocation during
sparse_init()", v6.

In sparse_init(), two temporary pointer arrays, usemap_map and map_map
are allocated with the size of NR_MEM_SECTIONS.  They are used to store
each memory section's usemap and mem map if marked as present.  In
5-level paging mode, this will cost 512M memory though they will be
released at the end of sparse_init().  System with few memory, like
kdump kernel which usually only has about 256M, will fail to boot
because of allocation failure if CONFIG_X86_5LEVEL=y.

In this patchset, optimize the memmap allocation code to only use
usemap_map and map_map with the size of nr_present_sections.  This makes
kdump kernel boot up with normal crashkernel='' setting when
CONFIG_X86_5LEVEL=y.

This patch (of 5):

nr_present_sections is used to record how many memory sections are
marked as present during system boot up, and will be used in the later
patch.

Link: http://lkml.kernel.org/r/20180228032657.32385-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai 7e010df53c mm: use special value SHRINKER_REGISTERING instead of list_empty() check
The patch introduces a special value SHRINKER_REGISTERING to use instead
of list_empty() to differ a registering shrinker from unregistered
shrinker.  Why we need that at all?

Shrinker registration is split in two parts.  The first one is
prealloc_shrinker(), which allocates shrinker memory and reserves ID in
shrinker_idr.  This function can fail.  The second is
register_shrinker_prepared(), and it finalizes the registration.  This
function actually makes shrinker available to be used from
shrink_slab(), and it can't fail.

One shrinker may be based on more then one LRU lists.  So, we never
clear the bit in memcg shrinker maps, when (one of) corresponding LRU
list becomes empty, since other LRU lists may be not empty.  See
superblock shrinker for example: it is based on two LRU lists:
s_inode_lru and s_dentry_lru.  We do not want to clear shrinker bit,
when there are no inodes in s_inode_lru, as s_dentry_lru may contain
dentries.

Instead of that, we use special algorithm to detect shrinkers having no
elements at all its LRU lists, and this is made in shrink_slab_memcg().
See the comment in this function for the details.

Also, in shrink_slab_memcg() we clear shrinker bit in the map, when we
meet unregistered shrinker (bit is set, while there is no a shrinker in
IDR).  Otherwise, we would have done that at the moment of shrinker
unregistration for all memcgs (and this looks worse, since iteration
over all memcg may take much time).  Also this would have imposed
restrictions on shrinker unregistration order for its users: they would
have had to guarantee, there are no new elements after
unregister_shrinker() (otherwise, a new added element would have set a
bit).

So, if we meet a set bit in map and no shrinker in IDR when we're
iterating over the map in shrink_slab_memcg(), this means the
corresponding shrinker is unregistered, and we must clear the bit.

Another case is shrinker registration.  We want two things there:

1) do_shrink_slab() can be called only for completely registered
   shrinkers;

2) shrinker internal lists may be populated in any order with
   register_shrinker_prepared() (let's talk on the example with sb).  Both
   of:

  a)list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru); [cpu0]
    memcg_set_shrinker_bit();                               [cpu0]
    ...
    register_shrinker_prepared();                           [cpu1]

  and

  b)register_shrinker_prepared();                           [cpu0]
    ...
    list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru); [cpu1]
    memcg_set_shrinker_bit();                               [cpu1]

   are legitimate.  We don't want to impose restriction here and to
   force people to use only (b) variant.  We don't want to force people to
   care, there is no elements in LRU lists before the shrinker is
   completely registered.  Internal users of LRU lists and shrinker code
   are two different subsystems, and they have to be closed in themselves
   each other.

In (a) case we have the bit set before shrinker is completely
registered.  We don't want do_shrink_slab() is called at this moment, so
we have to detect such the registering shrinkers.

Before this patch list_empty() (shrinker is not linked to the list)
check was used for that.  So, in (a) there could be a bit set, but we
don't call do_shrink_slab() unless shrinker is linked to the list.  It's
just an indicator, I just overloaded linking to the list.

This was not the best solution, since it's better not to touch the
shrinker memory from shrink_slab_memcg() before it's completely
registered (this also will be useful in the future to make shrink_slab()
completely lockless).

So, this patch introduces better way to detect registering shrinker,
which allows not to dereference shrinker memory.  It's just a ~0UL
value, which we insert into the IDR during ID allocation.  After
shrinker is ready to be used, we insert actual shrinker pointer in the
IDR, and it becomes available to shrink_slab_memcg().

We can't use NULL instead of this new value for this purpose as:
shrink_slab_memcg() already uses NULL to detect unregistered shrinkers,
and we don't want the function sees NULL and clears the bit, otherwise
(a) won't work.

This is the only thing the patch makes: the better way to detect
registering shrinker.  Nothing else this patch makes.

Also this gives a better assembler, but it's minor side of the patch:

Before:
  callq  <idr_find>
  mov    %rax,%r15
  test   %rax,%rax
  je     <shrink_slab_memcg+0x1d5>
  mov    0x20(%rax),%rax
  lea    0x20(%r15),%rdx
  cmp    %rax,%rdx
  je     <shrink_slab_memcg+0xbd>
  mov    0x8(%rsp),%edx
  mov    %r15,%rsi
  lea    0x10(%rsp),%rdi
  callq  <do_shrink_slab>

After:
  callq  <idr_find>
  mov    %rax,%r15
  lea    -0x1(%rax),%rax
  cmp    $0xfffffffffffffffd,%rax
  ja     <shrink_slab_memcg+0x1cd>
  mov    0x8(%rsp),%edx
  mov    %r15,%rsi
  lea    0x10(%rsp),%rdi
  callq  ffffffff810cefd0 <do_shrink_slab>

[ktkhai@virtuozzo.com: add #ifdef CONFIG_MEMCG_KMEM around idr_replace()]
  Link: http://lkml.kernel.org/r/758b8fec-7573-47eb-b26a-7b2847ae7b8c@virtuozzo.com
Link: http://lkml.kernel.org/r/153355467546.11522.4518015068123480218.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai ac7fb3ad27 mm/vmscan.c: move check for SHRINKER_NUMA_AWARE to do_shrink_slab()
In case of shrink_slab_memcg() we do not zero nid, when shrinker is not
numa-aware.  This is not a real problem, since currently all memcg-aware
shrinkers are numa-aware too (we have two: super_block shrinker and
workingset shrinker), but something may change in the future.

Link: http://lkml.kernel.org/r/153320759911.18959.8842396230157677671.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai f90280d6b7 mm/vmscan.c: clear shrinker bit if there are no objects related to memcg
To avoid further unneed calls of do_shrink_slab() for shrinkers, which
already do not have any charged objects in a memcg, their bits have to
be cleared.

This patch introduces a lockless mechanism to do that without races
without parallel list lru add.  After do_shrink_slab() returns
SHRINK_EMPTY the first time, we clear the bit and call it once again.
Then we restore the bit, if the new return value is different.

Note, that single smp_mb__after_atomic() in shrink_slab_memcg() covers
two situations:

1)list_lru_add()     shrink_slab_memcg
    list_add_tail()    for_each_set_bit() <--- read bit
                         do_shrink_slab() <--- missed list update (no barrier)
    <MB>                 <MB>
    set_bit()            do_shrink_slab() <--- seen list update

This situation, when the first do_shrink_slab() sees set bit, but it
doesn't see list update (i.e., race with the first element queueing), is
rare.  So we don't add <MB> before the first call of do_shrink_slab()
instead of this to do not slow down generic case.  Also, it's need the
second call as seen in below in (2).

2)list_lru_add()      shrink_slab_memcg()
    list_add_tail()     ...
    set_bit()           ...
  ...                   for_each_set_bit()
  do_shrink_slab()        do_shrink_slab()
    clear_bit()           ...
  ...                     ...
  list_lru_add()          ...
    list_add_tail()       clear_bit()
    <MB>                  <MB>
    set_bit()             do_shrink_slab()

The barriers guarantee that the second do_shrink_slab() in the right
side task sees list update if really cleared the bit.  This case is
drawn in the code comment.

[Results/performance of the patchset]

After the whole patchset applied the below test shows signify increase
of performance:

  $echo 1 > /sys/fs/cgroup/memory/memory.use_hierarchy
  $mkdir /sys/fs/cgroup/memory/ct
  $echo 4000M > /sys/fs/cgroup/memory/ct/memory.kmem.limit_in_bytes
      $for i in `seq 0 4000`; do mkdir /sys/fs/cgroup/memory/ct/$i;
			    echo $$ > /sys/fs/cgroup/memory/ct/$i/cgroup.procs;
			    mkdir -p s/$i; mount -t tmpfs $i s/$i;
			    touch s/$i/file; done

Then, 5 sequential calls of drop caches:

  $time echo 3 > /proc/sys/vm/drop_caches

1)Before:
  0.00user 13.78system 0:13.78elapsed 99%CPU
  0.00user 5.59system 0:05.60elapsed 99%CPU
  0.00user 5.48system 0:05.48elapsed 99%CPU
  0.00user 8.35system 0:08.35elapsed 99%CPU
  0.00user 8.34system 0:08.35elapsed 99%CPU

2)After
  0.00user 1.10system 0:01.10elapsed 99%CPU
  0.00user 0.00system 0:00.01elapsed 64%CPU
  0.00user 0.01system 0:00.01elapsed 82%CPU
  0.00user 0.00system 0:00.01elapsed 64%CPU
  0.00user 0.01system 0:00.01elapsed 82%CPU

The results show the performance increases at least in 548 times.

Shakeel Butt tested this patchset with fork-bomb on his configuration:

 > I created 255 memcgs, 255 ext4 mounts and made each memcg create a
 > file containing few KiBs on corresponding mount. Then in a separate
 > memcg of 200 MiB limit ran a fork-bomb.
 >
 > I ran the "perf record -ag -- sleep 60" and below are the results:
 >
 > Without the patch series:
 > Samples: 4M of event 'cycles', Event count (approx.): 3279403076005
 > +  36.40%            fb.sh  [kernel.kallsyms]    [k] shrink_slab
 > +  18.97%            fb.sh  [kernel.kallsyms]    [k] list_lru_count_one
 > +   6.75%            fb.sh  [kernel.kallsyms]    [k] super_cache_count
 > +   0.49%            fb.sh  [kernel.kallsyms]    [k] down_read_trylock
 > +   0.44%            fb.sh  [kernel.kallsyms]    [k] mem_cgroup_iter
 > +   0.27%            fb.sh  [kernel.kallsyms]    [k] up_read
 > +   0.21%            fb.sh  [kernel.kallsyms]    [k] osq_lock
 > +   0.13%            fb.sh  [kernel.kallsyms]    [k] shmem_unused_huge_count
 > +   0.08%            fb.sh  [kernel.kallsyms]    [k] shrink_node_memcg
 > +   0.08%            fb.sh  [kernel.kallsyms]    [k] shrink_node
 >
 > With the patch series:
 > Samples: 4M of event 'cycles', Event count (approx.): 2756866824946
 > +  47.49%            fb.sh  [kernel.kallsyms]    [k] down_read_trylock
 > +  30.72%            fb.sh  [kernel.kallsyms]    [k] up_read
 > +   9.51%            fb.sh  [kernel.kallsyms]    [k] mem_cgroup_iter
 > +   1.69%            fb.sh  [kernel.kallsyms]    [k] shrink_node_memcg
 > +   1.35%            fb.sh  [kernel.kallsyms]    [k] mem_cgroup_protected
 > +   1.05%            fb.sh  [kernel.kallsyms]    [k] queued_spin_lock_slowpath
 > +   0.85%            fb.sh  [kernel.kallsyms]    [k] _raw_spin_lock
 > +   0.78%            fb.sh  [kernel.kallsyms]    [k] lruvec_lru_size
 > +   0.57%            fb.sh  [kernel.kallsyms]    [k] shrink_node
 > +   0.54%            fb.sh  [kernel.kallsyms]    [k] queue_work_on
 > +   0.46%            fb.sh  [kernel.kallsyms]    [k] shrink_slab_memcg

[ktkhai@virtuozzo.com: v9]
  Link: http://lkml.kernel.org/r/153112561772.4097.11011071937553113003.stgit@localhost.localdomain
Link: http://lkml.kernel.org/r/153063070859.1818.11870882950920963480.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai 9b996468cf mm: add SHRINK_EMPTY shrinker methods return value
We need to distinguish the situations when shrinker has very small
amount of objects (see vfs_pressure_ratio() called from
super_cache_count()), and when it has no objects at all.  Currently, in
the both of these cases, shrinker::count_objects() returns 0.

The patch introduces new SHRINK_EMPTY return value, which will be used
for "no objects at all" case.  It's is a refactoring mostly, as
SHRINK_EMPTY is replaced by 0 by all callers of do_shrink_slab() in this
patch, and all the magic will happen in further.

Link: http://lkml.kernel.org/r/153063069574.1818.11037751256699341813.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Vladimir Davydov aeed1d325d mm/vmscan.c: generalize shrink_slab() calls in shrink_node()
The patch makes shrink_slab() be called for root_mem_cgroup in the same
way as it's called for the rest of cgroups.  This simplifies the logic
and improves the readability.

[ktkhai@virtuozzo.com: wrote changelog]
Link: http://lkml.kernel.org/r/153063068338.1818.11496084754797453962.stgit@localhost.localdomain
Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai b0dedc49a2 mm/vmscan.c: iterate only over charged shrinkers during memcg shrink_slab()
Using the preparations made in previous patches, in case of memcg
shrink, we may avoid shrinkers, which are not set in memcg's shrinkers
bitmap.  To do that, we separate iterations over memcg-aware and
!memcg-aware shrinkers, and memcg-aware shrinkers are chosen via
for_each_set_bit() from the bitmap.  In case of big nodes, having many
isolated environments, this gives significant performance growth.  See
next patches for the details.

Note that the patch does not respect to empty memcg shrinkers, since we
never clear the bitmap bits after we set it once.  Their shrinkers will
be called again, with no shrinked objects as result.  This functionality
is provided by next patches.

[ktkhai@virtuozzo.com: v9]
  Link: http://lkml.kernel.org/r/153112558507.4097.12713813335683345488.stgit@localhost.localdomain
Link: http://lkml.kernel.org/r/153063066653.1818.976035462801487910.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai fae91d6d8b mm/list_lru.c: set bit in memcg shrinker bitmap on first list_lru item appearance
Introduce set_shrinker_bit() function to set shrinker-related bit in
memcg shrinker bitmap, and set the bit after the first item is added and
in case of reparenting destroyed memcg's items.

This will allow next patch to make shrinkers be called only, in case of
they have charged objects at the moment, and to improve shrink_slab()
performance.

[ktkhai@virtuozzo.com: v9]
  Link: http://lkml.kernel.org/r/153112557572.4097.17315791419810749985.stgit@localhost.localdomain
Link: http://lkml.kernel.org/r/153063065671.1818.15914674956134687268.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai dfd2f10ccf mm/memcontrol.c: export mem_cgroup_is_root()
This will be used in next patch.

Link: http://lkml.kernel.org/r/153063064347.1818.1987011484100392706.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai 3b82c4dcc2 mm/list_lru.c: pass lru argument to memcg_drain_list_lru_node()
This is just refactoring to allow next patches to have lru pointer in
memcg_drain_list_lru_node().

Link: http://lkml.kernel.org/r/153063063164.1818.55009531386089350.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai 9bec5c35bf mm/list_lru: pass dst_memcg argument to memcg_drain_list_lru_node()
This is just refactoring to allow the next patches to have dst_memcg
pointer in memcg_drain_list_lru_node().

Link: http://lkml.kernel.org/r/153063062118.1818.2761273817739499749.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai 44bd4a4759 mm/list_lru.c: add memcg argument to list_lru_from_kmem()
This is just refactoring to allow the next patches to have memcg pointer
in list_lru_from_kmem().

Link: http://lkml.kernel.org/r/153063060664.1818.9541345386733498582.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai c92e8e10ca fs: propagate shrinker::id to list_lru
Add list_lru::shrinker_id field and populate it by registered shrinker
id.

This will be used to set correct bit in memcg shrinkers map by lru code
in next patches, after there appeared the first related to memcg element
in list_lru.

Link: http://lkml.kernel.org/r/153063059758.1818.14866596416857717800.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:31 -07:00
Kirill Tkhai 39887653aa mm/workingset.c: refactor workingset_init()
Use prealloc_shrinker()/register_shrinker_prepared() instead of
register_shrinker().  This will be used in next patch.

[ktkhai@virtuozzo.com: v9]
  Link: http://lkml.kernel.org/r/153112550112.4097.16606173020912323761.stgit@localhost.localdomain
Link: http://lkml.kernel.org/r/153063057666.1818.17625951186610808734.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Kirill Tkhai 0a4465d340 mm, memcg: assign memcg-aware shrinkers bitmap to memcg
Imagine a big node with many cpus, memory cgroups and containers.  Let
we have 200 containers, every container has 10 mounts, and 10 cgroups.
All container tasks don't touch foreign containers mounts.  If there is
intensive pages write, and global reclaim happens, a writing task has to
iterate over all memcgs to shrink slab, before it's able to go to
shrink_page_list().

Iteration over all the memcg slabs is very expensive: the task has to
visit 200 * 10 = 2000 shrinkers for every memcg, and since there are
2000 memcgs, the total calls are 2000 * 2000 = 4000000.

So, the shrinker makes 4 million do_shrink_slab() calls just to try to
isolate SWAP_CLUSTER_MAX pages in one of the actively writing memcg via
shrink_page_list().  I've observed a node spending almost 100% in
kernel, making useless iteration over already shrinked slab.

This patch adds bitmap of memcg-aware shrinkers to memcg.  The size of
the bitmap depends on bitmap_nr_ids, and during memcg life it's
maintained to be enough to fit bitmap_nr_ids shrinkers.  Every bit in
the map is related to corresponding shrinker id.

Next patches will maintain set bit only for really charged memcg.  This
will allow shrink_slab() to increase its performance in significant way.
See the last patch for the numbers.

[ktkhai@virtuozzo.com: v9]
  Link: http://lkml.kernel.org/r/153112549031.4097.3576147070498769979.stgit@localhost.localdomain
[ktkhai@virtuozzo.com: add comment to mem_cgroup_css_online()]
  Link: http://lkml.kernel.org/r/521f9e5f-c436-b388-fe83-4dc870bfb489@virtuozzo.com
Link: http://lkml.kernel.org/r/153063056619.1818.12550500883688681076.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Kirill Tkhai b05706f100 mm/memcontrol.c: move up for_each_mem_cgroup{, _tree} defines
Next patch requires these defines are above their current position, so
here they are moved to declarations.

Link: http://lkml.kernel.org/r/153063055665.1818.5200425793649695598.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Kirill Tkhai b4c2b231c3 mm: assign id to every memcg-aware shrinker
Introduce shrinker::id number, which is used to enumerate memcg-aware
shrinkers.  The number start from 0, and the code tries to maintain it
as small as possible.

This will be used to represent a memcg-aware shrinkers in memcg
shrinkers map.

Since all memcg-aware shrinkers are based on list_lru, which is
per-memcg in case of !CONFIG_MEMCG_KMEM only, the new functionality will
be under this config option.

[ktkhai@virtuozzo.com: v9]
  Link: http://lkml.kernel.org/r/153112546435.4097.10607140323811756557.stgit@localhost.localdomain
Link: http://lkml.kernel.org/r/153063054586.1818.6041047871606697364.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Kirill Tkhai 84c07d11aa mm: introduce CONFIG_MEMCG_KMEM as combination of CONFIG_MEMCG && !CONFIG_SLOB
Introduce new config option, which is used to replace repeating
CONFIG_MEMCG && !CONFIG_SLOB pattern.  Next patches add a little more
memcg+kmem related code, so let's keep the defines more clearly.

Link: http://lkml.kernel.org/r/153063053670.1818.15013136946600481138.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Kirill Tkhai e0295238e5 mm/list_lru.c: combine code under the same define
Patch series "Improve shrink_slab() scalability (old complexity was O(n^2), new is O(n))", v8.

This patcheset solves the problem with slow shrink_slab() occuring on
the machines having many shrinkers and memory cgroups (i.e., with many
containers).  The problem is complexity of shrink_slab() is O(n^2) and
it grows too fast with the growth of containers numbers.

Let us have 200 containers, and every container has 10 mounts and 10
cgroups.  All container tasks are isolated, and they don't touch foreign
containers mounts.

In case of global reclaim, a task has to iterate all over the memcgs and
to call all the memcg-aware shrinkers for all of them.  This means, the
task has to visit 200 * 10 = 2000 shrinkers for every memcg, and since
there are 2000 memcgs, the total calls of do_shrink_slab() are 2000 *
2000 = 4000000.

4 million calls are not a number operations, which can takes 1 cpu
cycle.  E.g., super_cache_count() accesses at least two lists, and makes
arifmetical calculations.  Even, if there are no charged objects, we do
these calculations, and replaces cpu caches by read memory.  I observed
nodes spending almost 100% time in kernel, in case of intensive writing
and global reclaim.  The writer consumes pages fast, but it's need to
shrink_slab() before the reclaimer reached shrink pages function (and
frees SWAP_CLUSTER_MAX pages).  Even if there is no writing, the
iterations just waste the time, and slows reclaim down.

Let's see the small test below:

  $echo 1 > /sys/fs/cgroup/memory/memory.use_hierarchy
  $mkdir /sys/fs/cgroup/memory/ct
  $echo 4000M > /sys/fs/cgroup/memory/ct/memory.kmem.limit_in_bytes
  $for i in `seq 0 4000`;
          do mkdir /sys/fs/cgroup/memory/ct/$i;
          echo $$ > /sys/fs/cgroup/memory/ct/$i/cgroup.procs;
          mkdir -p s/$i; mount -t tmpfs $i s/$i; touch s/$i/file;
  done

Then, let's see drop caches time (5 sequential calls):

  $time echo 3 > /proc/sys/vm/drop_caches

  0.00user 13.78system 0:13.78elapsed 99%CPU
  0.00user 5.59system 0:05.60elapsed 99%CPU
  0.00user 5.48system 0:05.48elapsed 99%CPU
  0.00user 8.35system 0:08.35elapsed 99%CPU
  0.00user 8.34system 0:08.35elapsed 99%CPU

The last four calls don't actually shrink anything.  So, the iterations
over slab shrinkers take 5.48 seconds.  Not so good for scalability.

The patchset solves the problem by making shrink_slab() of O(n)
complexity.  There are following functional actions:

1) Assign id to every registered memcg-aware shrinker.

2) Maintain per-memcgroup bitmap of memcg-aware shrinkers, and set a
   shrinker-related bit after the first element is added to lru list
   (also, when removed child memcg elements are reparanted).

3) Split memcg-aware shrinkers and !memcg-aware shrinkers, and call a
   shrinker if its bit is set in memcg's shrinker bitmap.  (Also, there is
   a functionality to clear the bit, after last element is shrinked).

This gives significant performance increase.  The result after patchset
is applied:

  $time echo 3 > /proc/sys/vm/drop_caches

  0.00user 1.10system 0:01.10elapsed 99%CPU
  0.00user 0.00system 0:00.01elapsed 64%CPU
  0.00user 0.01system 0:00.01elapsed 82%CPU
  0.00user 0.00system 0:00.01elapsed 64%CPU
  0.00user 0.01system 0:00.01elapsed 82%CPU

The results show the performance increases at least in 548 times.

So, the patchset makes shrink_slab() of less complexity and improves the
performance in such types of load I pointed.  This will give a profit in
case of !global reclaim case, since there also will be less
do_shrink_slab() calls.

This patch (of 17):

These two pairs of blocks of code are under the same #ifdef #else
#endif.

Link: http://lkml.kernel.org/r/153063052519.1818.9393587113056959488.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Roman Gushchin <guro@fb.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Waiman Long <longman@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Mike Rapoport a36aab890c mm/memblock.c: replace u64 with phys_addr_t where appropriate
Most functions in memblock already use phys_addr_t to represent a
physical address with __memblock_free_late() being an exception.

This patch replaces u64 with phys_addr_t in __memblock_free_late() and
switches several format strings from %llx to %pa to avoid casting from
phys_addr_t to u64.

Link: http://lkml.kernel.org/r/1530637506-1256-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Oscar Salvador 4e40987f12 mm/sparse.c: make sparse_init_one_section void and remove check
sparse_init_one_section() is being called from two sites: sparse_init()
and sparse_add_one_section().  The former calls it from a
for_each_present_section_nr() loop, and the latter marks the section as
present before calling it.  This means that when
sparse_init_one_section() gets called, we already know that the section
is present.  So there is no point to double check that in the function.

This removes the check and makes the function void.

[ross.zwisler@linux.intel.com: fix error path in sparse_add_one_section]
  Link: http://lkml.kernel.org/r/20180706190658.6873-1-ross.zwisler@linux.intel.com
[ross.zwisler@linux.intel.com: simplification suggested by Oscar]
  Link: http://lkml.kernel.org/r/20180706223358.742-1-ross.zwisler@linux.intel.com
Link: http://lkml.kernel.org/r/20180702154325.12196-1-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Michal Hocko 29ef680ae7 memcg, oom: move out_of_memory back to the charge path
Commit 3812c8c8f3 ("mm: memcg: do not trap chargers with full
callstack on OOM") has changed the ENOMEM semantic of memcg charges.
Rather than invoking the oom killer from the charging context it delays
the oom killer to the page fault path (pagefault_out_of_memory).  This
in turn means that many users (e.g.  slab or g-u-p) will get ENOMEM when
the corresponding memcg hits the hard limit and the memcg is is OOM.
This is behavior is inconsistent with !memcg case where the oom killer
is invoked from the allocation context and the allocator keeps retrying
until it succeeds.

The difference in the behavior is user visible.  mmap(MAP_POPULATE)
might result in not fully populated ranges while the mmap return code
doesn't tell that to the userspace.  Random syscalls might fail with
ENOMEM etc.

The primary motivation of the different memcg oom semantic was the
deadlock avoidance.  Things have changed since then, though.  We have an
async oom teardown by the oom reaper now and so we do not have to rely
on the victim to tear down its memory anymore.  Therefore we can return
to the original semantic as long as the memcg oom killer is not handed
over to the users space.

There is still one thing to be careful about here though.  If the oom
killer is not able to make any forward progress - e.g.  because there is
no eligible task to kill - then we have to bail out of the charge path
to prevent from same class of deadlocks.  We have basically two options
here.  Either we fail the charge with ENOMEM or force the charge and
allow overcharge.  The first option has been considered more harmful
than useful because rare inconsistencies in the ENOMEM behavior is hard
to test for and error prone.  Basically the same reason why the page
allocator doesn't fail allocations under such conditions.  The later
might allow runaways but those should be really unlikely unless somebody
misconfigures the system.  E.g.  allowing to migrate tasks away from the
memcg to a different unlimited memcg with move_charge_at_immigrate
disabled.

Link: http://lkml.kernel.org/r/20180628151101.25307-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Mike Rapoport d39f8fb4b7 mm: make DEFERRED_STRUCT_PAGE_INIT explicitly depend on SPARSEMEM
The deferred memory initialization relies on section definitions, e.g
PAGES_PER_SECTION, that are only available when CONFIG_SPARSEMEM=y on
most architectures.

Initially DEFERRED_STRUCT_PAGE_INIT depended on explicit
ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT configuration option, but since
the commit 2e3ca40f03 ("mm: relax deferred struct page
requirements") this requirement was relaxed and now it is possible to
enable DEFERRED_STRUCT_PAGE_INIT on architectures that support
DISCONTINGMEM and NO_BOOTMEM which causes build failures.

For instance, setting SMP=y and DEFERRED_STRUCT_PAGE_INIT=y on arc
causes the following build failure:

    CC      mm/page_alloc.o
  mm/page_alloc.c: In function 'update_defer_init':
  mm/page_alloc.c:321:14: error: 'PAGES_PER_SECTION'
  undeclared (first use in this function); did you mean 'USEC_PER_SEC'?
        (pfn & (PAGES_PER_SECTION - 1)) == 0) {
                ^~~~~~~~~~~~~~~~~
                USEC_PER_SEC
  mm/page_alloc.c:321:14: note: each undeclared identifier is reported only once for each function it appears in
  In file included from include/linux/cache.h:5:0,
                   from include/linux/printk.h:9,
                   from include/linux/kernel.h:14,
                   from include/asm-generic/bug.h:18,
                   from arch/arc/include/asm/bug.h:32,
                   from include/linux/bug.h:5,
                   from include/linux/mmdebug.h:5,
                   from include/linux/mm.h:9,
                   from mm/page_alloc.c:18:
  mm/page_alloc.c: In function 'deferred_grow_zone':
  mm/page_alloc.c:1624:52: error: 'PAGES_PER_SECTION' undeclared (first use in this function); did you mean 'USEC_PER_SEC'?
    unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION);
                                                      ^
  include/uapi/linux/kernel.h:11:47: note: in definition of macro '__ALIGN_KERNEL_MASK'
   #define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))
                                                 ^~~~
  include/linux/kernel.h:58:22: note: in expansion of macro '__ALIGN_KERNEL'
   #define ALIGN(x, a)  __ALIGN_KERNEL((x), (a))
                        ^~~~~~~~~~~~~~
  mm/page_alloc.c:1624:34: note: in expansion of macro 'ALIGN'
    unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION);
                                    ^~~~~
  In file included from include/asm-generic/bug.h:18:0,
                   from arch/arc/include/asm/bug.h:32,
                   from include/linux/bug.h:5,
                   from include/linux/mmdebug.h:5,
                   from include/linux/mm.h:9,
                   from mm/page_alloc.c:18:
  mm/page_alloc.c: In function 'free_area_init_node':
  mm/page_alloc.c:6379:50: error: 'PAGES_PER_SECTION' undeclared (first use in this function); did you mean 'USEC_PER_SEC'?
    pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
                                                    ^
  include/linux/kernel.h:812:22: note: in definition of macro '__typecheck'
     (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                        ^
  include/linux/kernel.h:836:24: note: in expansion of macro '__safe_cmp'
    __builtin_choose_expr(__safe_cmp(x, y), \
                          ^~~~~~~~~~
  include/linux/kernel.h:904:27: note: in expansion of macro '__careful_cmp'
   #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
                             ^~~~~~~~~~~~~
  mm/page_alloc.c:6379:29: note: in expansion of macro 'min_t'
    pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
                               ^~~~~
  include/linux/kernel.h:836:2: error: first argument to '__builtin_choose_expr' not a constant
    __builtin_choose_expr(__safe_cmp(x, y), \
    ^
  include/linux/kernel.h:904:27: note: in expansion of macro '__careful_cmp'
   #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
                             ^~~~~~~~~~~~~
  mm/page_alloc.c:6379:29: note: in expansion of macro 'min_t'
    pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
                               ^~~~~
  scripts/Makefile.build:317: recipe for target 'mm/page_alloc.o' failed

Let's make the DEFERRED_STRUCT_PAGE_INIT explicitly depend on SPARSEMEM
as the systems that support DISCONTIGMEM do not seem to have that huge
amounts of memory that would make DEFERRED_STRUCT_PAGE_INIT relevant.

Link: http://lkml.kernel.org/r/1530279308-24988-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Andrey Ryabinin 0207df4fa1 kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN
KASAN learns about hotadded memory via the memory hotplug notifier.
devm_memremap_pages() intentionally skips calling memory hotplug
notifiers.  So KASAN doesn't know anything about new memory added by
devm_memremap_pages().  This causes a crash when KASAN tries to access
non-existent shadow memory:

 BUG: unable to handle kernel paging request at ffffed0078000000
 RIP: 0010:check_memory_region+0x82/0x1e0
 Call Trace:
  memcpy+0x1f/0x50
  pmem_do_bvec+0x163/0x720
  pmem_make_request+0x305/0xac0
  generic_make_request+0x54f/0xcf0
  submit_bio+0x9c/0x370
  submit_bh_wbc+0x4c7/0x700
  block_read_full_page+0x5ef/0x870
  do_read_cache_page+0x2b8/0xb30
  read_dev_sector+0xbd/0x3f0
  read_lba.isra.0+0x277/0x670
  efi_partition+0x41a/0x18f0
  check_partition+0x30d/0x5e9
  rescan_partitions+0x18c/0x840
  __blkdev_get+0x859/0x1060
  blkdev_get+0x23f/0x810
  __device_add_disk+0x9c8/0xde0
  pmem_attach_disk+0x9a8/0xf50
  nvdimm_bus_probe+0xf3/0x3c0
  driver_probe_device+0x493/0xbd0
  bus_for_each_drv+0x118/0x1b0
  __device_attach+0x1cd/0x2b0
  bus_probe_device+0x1ac/0x260
  device_add+0x90d/0x1380
  nd_async_device_register+0xe/0x50
  async_run_entry_fn+0xc3/0x5d0
  process_one_work+0xa0a/0x1810
  worker_thread+0x87/0xe80
  kthread+0x2d7/0x390
  ret_from_fork+0x3a/0x50

Add kasan_add_zero_shadow()/kasan_remove_zero_shadow() - post mm_init()
interface to map/unmap kasan_zero_page at requested virtual addresses.
And use it to add/remove the shadow memory for hotplugged/unplugged
device memory.

Link: http://lkml.kernel.org/r/20180629164932.740-1-aryabinin@virtuozzo.com
Fixes: 41e94a8513 ("add devm_memremap_pages")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Song Liu 50f8b92f21 mm: thp: pass correct vm_flags to hugepage_vma_check()
khugepaged_enter_vma_merge() passes a stale vma->vm_flags to
hugepage_vma_check().  The argument vm_flags contains the latest value.
Therefore, it is necessary to pass this vm_flags into
hugepage_vma_check().

With this bug, madvise(MADV_HUGEPAGE) for mmap files in shmem fails to
put memory in huge pages.  Here is an example of failed madvise():

   /* mount /dev/shm with huge=advise:
    *     mount -o remount,huge=advise /dev/shm */
   /* create file /dev/shm/huge */
   #define HUGE_FILE "/dev/shm/huge"

   fd = open(HUGE_FILE, O_RDONLY);
   ptr = mmap(NULL, FILE_SIZE, PROT_READ, MAP_PRIVATE, fd, 0);
   ret = madvise(ptr, FILE_SIZE, MADV_HUGEPAGE);

madvise() will return 0, but this memory region is never put in huge
page (check from /proc/meminfo: ShmemHugePages).

Link: http://lkml.kernel.org/r/20180629181752.792831-1-songliubraving@fb.com
Fixes: 02b75dc8160d ("mm: thp: register mm for khugepaged when merging vma for shmem")
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Andrey Ryabinin a718e28f53 mm/fadvise.c: fix signed overflow UBSAN complaint
Signed integer overflow is undefined according to the C standard.  The
overflow in ksys_fadvise64_64() is deliberate, but since it is signed
overflow, UBSAN complains:

	UBSAN: Undefined behaviour in mm/fadvise.c:76:10
	signed integer overflow:
	4 + 9223372036854775805 cannot be represented in type 'long long int'

Use unsigned types to do math.  Unsigned overflow is defined so UBSAN
will not complain about it.  This patch doesn't change generated code.

[akpm@linux-foundation.org: add comment explaining the casts]
Link: http://lkml.kernel.org/r/20180629184453.7614-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: <icytxw@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Colin Ian King 31f21da181 mm/swap_slots.c: make swap_slots_cache_mutex and swap_slots_cache_enable_mutex static
The mutexes swap_slots_cache_mutex and swap_slots_cache_enable_mutex are
local to the source and do not need to be in global scope, so make them
static.

Cleans up sparse warnings:
  symbol 'swap_slots_cache_mutex' was not declared. Should it be static?
  symbol 'swap_slots_cache_enable_mutex' was not declared. Should it be static?

Link: http://lkml.kernel.org/r/20180624182536.4937-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Colin Ian King 4d0a5402f5 mm/zsmalloc.c: make several functions and a struct static
The functions zs_page_isolate, zs_page_migrate, zs_page_putback,
lock_zspage, trylock_zspage and structure zsmalloc_aops are local to
source and do not need to be in global scope, so make them static.

Cleans up sparse warnings:
  symbol 'zs_page_isolate' was not declared. Should it be static?
  symbol 'zs_page_migrate' was not declared. Should it be static?
  symbol 'zs_page_putback' was not declared. Should it be static?
  symbol 'zsmalloc_aops' was not declared. Should it be static?
  symbol 'lock_zspage' was not declared. Should it be static?
  symbol 'trylock_zspage' was not declared. Should it be static?

[arnd@arndb.de: hide unused lock_zspage]
  Link: http://lkml.kernel.org/r/20180706130924.3891230-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20180624213322.13776-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Greg Thelen dcfe4df3d5 mm/page-writeback.c: update stale account_page_redirty() comment
Commit 93f78d8828 ("writeback: move backing_dev_info->bdi_stat[] into
bdi_writeback") replaced BDI_DIRTIED with WB_DIRTIED in
account_page_redirty().  Update comment to track that change.

  BDI_DIRTIED => WB_DIRTIED
  BDI_WRITTEN => WB_WRITTEN

Link: http://lkml.kernel.org/r/20180625171526.173483-1-gthelen@google.com
Signed-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Shakeel Butt f745c6f5fe fs, mm: account buffer_head to kmemcg
The buffer_head can consume a significant amount of system memory and is
directly related to the amount of page cache.  In our production
environment we have observed that a lot of machines are spending a
significant amount of memory as buffer_head and can not be left as
system memory overhead.

Charging buffer_head is not as simple as adding __GFP_ACCOUNT to the
allocation.  The buffer_heads can be allocated in a memcg different from
the memcg of the page for which buffer_heads are being allocated.  One
concrete example is memory reclaim.  The reclaim can trigger I/O of
pages of any memcg on the system.  So, the right way to charge
buffer_head is to extract the memcg from the page for which buffer_heads
are being allocated and then use targeted memcg charging API.

[shakeelb@google.com: use __GFP_ACCOUNT for directed memcg charging]
  Link: http://lkml.kernel.org/r/20180702220208.213380-1-shakeelb@google.com
Link: http://lkml.kernel.org/r/20180627191250.209150-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Shakeel Butt d46eb14b73 fs: fsnotify: account fsnotify metadata to kmemcg
Patch series "Directed kmem charging", v8.

The Linux kernel's memory cgroup allows limiting the memory usage of the
jobs running on the system to provide isolation between the jobs.  All
the kernel memory allocated in the context of the job and marked with
__GFP_ACCOUNT will also be included in the memory usage and be limited
by the job's limit.

The kernel memory can only be charged to the memcg of the process in
whose context kernel memory was allocated.  However there are cases
where the allocated kernel memory should be charged to the memcg
different from the current processes's memcg.  This patch series
contains two such concrete use-cases i.e.  fsnotify and buffer_head.

The fsnotify event objects can consume a lot of system memory for large
or unlimited queues if there is either no or slow listener.  The events
are allocated in the context of the event producer.  However they should
be charged to the event consumer.  Similarly the buffer_head objects can
be allocated in a memcg different from the memcg of the page for which
buffer_head objects are being allocated.

To solve this issue, this patch series introduces mechanism to charge
kernel memory to a given memcg.  In case of fsnotify events, the memcg
of the consumer can be used for charging and for buffer_head, the memcg
of the page can be charged.  For directed charging, the caller can use
the scope API memalloc_[un]use_memcg() to specify the memcg to charge
for all the __GFP_ACCOUNT allocations within the scope.

This patch (of 2):

A lot of memory can be consumed by the events generated for the huge or
unlimited queues if there is either no or slow listener.  This can cause
system level memory pressure or OOMs.  So, it's better to account the
fsnotify kmem caches to the memcg of the listener.

However the listener can be in a different memcg than the memcg of the
producer and these allocations happen in the context of the event
producer.  This patch introduces remote memcg charging API which the
producer can use to charge the allocations to the memcg of the listener.

There are seven fsnotify kmem caches and among them allocations from
dnotify_struct_cache, dnotify_mark_cache, fanotify_mark_cache and
inotify_inode_mark_cachep happens in the context of syscall from the
listener.  So, SLAB_ACCOUNT is enough for these caches.

The objects from fsnotify_mark_connector_cachep are not accounted as
they are small compared to the notification mark or events and it is
unclear whom to account connector to since it is shared by all events
attached to the inode.

The allocations from the event caches happen in the context of the event
producer.  For such caches we will need to remote charge the allocations
to the listener's memcg.  Thus we save the memcg reference in the
fsnotify_group structure of the listener.

This patch has also moved the members of fsnotify_group to keep the size
same, at least for 64 bit build, even with additional member by filling
the holes.

[shakeelb@google.com: use GFP_KERNEL_ACCOUNT rather than open-coding it]
  Link: http://lkml.kernel.org/r/20180702215439.211597-1-shakeelb@google.com
Link: http://lkml.kernel.org/r/20180627191250.209150-2-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Luis R. Rodriguez 1a9b4b3d75 mm: provide a fallback for PAGE_KERNEL_EXEC for architectures
Some architectures just don't have PAGE_KERNEL_EXEC.  The mm/nommu.c and
mm/vmalloc.c code have been using PAGE_KERNEL as a fallback for years.
Move this fallback to asm-generic.

Link: http://lkml.kernel.org/r/20180510185507.2439-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Oscar Salvador 4fbce63391 mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()
link_mem_sections() and walk_memory_range() share most of the code, so
we can use convert link_mem_sections() into a dummy function that calls
walk_memory_range() with a callback to register_mem_sect_under_node().

This patch converts register_mem_sect_under_node() in order to match a
walk_memory_range's callback, getting rid of the check_nid argument and
checking instead if the system is still boothing, since we only have to
check for the nid if the system is in such state.

Link: http://lkml.kernel.org/r/20180622111839.10071-4-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Oscar Salvador d5b6f6a361 mm/memory_hotplug.c: call register_mem_sect_under_node()
When hotplugging memory, it is possible that two calls are being made to
register_mem_sect_under_node().

One comes from __add_section()->hotplug_memory_register() and the other
from add_memory_resource()->link_mem_sections() if we had to register a
new node.

In case we had to register a new node, hotplug_memory_register() will
only handle/allocate the memory_block's since
register_mem_sect_under_node() will return right away because the node
it is not online yet.

I think it is better if we leave hotplug_memory_register() to
handle/allocate only memory_block's and make link_mem_sections() to call
register_mem_sect_under_node().

So this patch removes the call to register_mem_sect_under_node() from
hotplug_memory_register(), and moves the call to link_mem_sections() out
of the condition, so it will always be called.  In this way we only have
one place where the memory sections are registered.

Link: http://lkml.kernel.org/r/20180622111839.10071-3-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Oscar Salvador b9ff036082 mm/memory_hotplug.c: make add_memory_resource use __try_online_node
This is a small cleanup for the memhotplug code.  A lot more could be
done, but it is better to start somewhere.  I tried to unify/remove
duplicated code.

The following is what this patchset does:

1) add_memory_resource() has code to allocate a node in case it was
   offline.  Since try_online_node has some code for that as well, I just
   made add_memory_resource() to use that so we can remove duplicated
   code..  This is better explained in patch 1/4.

2) register_mem_sect_under_node() will be called only from
   link_mem_sections()

3) Make register_mem_sect_under_node() a callback of
   walk_memory_range()

4) Drop unnecessary checks from register_mem_sect_under_node()

I have done some tests and I could not see anything broken because of
this patchset.

add_memory_resource() contains code to allocate a new node in case it is
necessary.  Since try_online_node() also has some code for this purpose,
let us make use of that and remove duplicate code.

This introduces __try_online_node(), which is called by
add_memory_resource() and try_online_node().  __try_online_node() has
two new parameters, start_addr of the node, and if the node should be
onlined and registered right away.  This is always wanted if we are
calling from do_cpu_up(), but not when we are calling from memhotplug
code.  Nothing changes from the point of view of the users of
try_online_node(), since try_online_node passes start_addr=0 and
online_node=true to __try_online_node().

Link: http://lkml.kernel.org/r/20180622111839.10071-2-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Andrew Morton 930eaac5ee mm/list_lru.c: fold __list_lru_count_one() into its caller
__list_lru_count_one() has a single callsite.

Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Sebastian Andrzej Siewior 6ca342d020 mm: workingset: make shadow_lru_isolate() use locking suffix
shadow_lru_isolate() disables interrupts and acquires a lock.  It could
use spin_lock_irq() instead.  It also uses local_irq_enable() while it
could use spin_unlock_irq()/xa_unlock_irq().

Use proper suffix for lock/unlock in order to enable/disable interrupts
during release/acquire of a lock.

Link: http://lkml.kernel.org/r/20180622151221.28167-3-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Sebastian Andrzej Siewior ae1e16da14 mm: workingset: remove local_irq_disable() from count_shadow_nodes()
Patch series "mm: use irq locking suffix instead local_irq_disable()".

A small series which avoids using local_irq_disable()/local_irq_enable()
but instead does spin_lock_irq()/spin_unlock_irq() so it is within the
context of the lock which it belongs to.  Patch #1 is a cleanup where
local_irq_.*() remained after the lock was removed.

This patch (of 2):

In 0c7c1bed7e ("mm: make counting of list_lru_one::nr_items lockless")
the

	spin_lock(&nlru->lock);

statement was replaced with

	rcu_read_lock();

in __list_lru_count_one().  The comment in count_shadow_nodes() says
that the local_irq_disable() is required because the lock must be
acquired with disabled interrupts and (spin_lock()) does not do so.
Since the lock is replaced with rcu_read_lock() the local_irq_disable()
is no longer needed.  The code path is

  list_lru_shrink_count()
    -> list_lru_count_one()
      -> __list_lru_count_one()
        -> rcu_read_lock()
        -> list_lru_from_memcg_idx()
        -> rcu_read_unlock()

Remove the local_irq_disable() statement.

Link: http://lkml.kernel.org/r/20180622151221.28167-2-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Michal Hocko 9ea9a68064 mm: drop VM_BUG_ON from __get_free_pages
There is no real reason to blow up just because the caller doesn't know
that __get_free_pages cannot return highmem pages.  Simply fix that up
silently.  Even if we have some confused users such a fixup will not be
harmful.

[akpm@linux-foundation.org: mask off __GFP_HIGHMEM]
Link: http://lkml.kernel.org/r/20180622162841.25114-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiankang Chen <chenjiankang1@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Huang Ying 974e6d66b6 mm, hugetlbfs: pass fault address to cow handler
This is to take better advantage of the general huge page copying
optimization.  Where, the target subpage will be copied last to avoid
the cache lines of target subpage to be evicted when copying other
subpages.  This works better if the address of the target subpage is
available when copying huge page.  So hugetlbfs page fault handlers are
changed to pass that information to hugetlb_cow().  This will benefit
workloads which don't access the begin of the hugetlbfs huge page after
the page fault under heavy cache contention.

Link: http://lkml.kernel.org/r/20180524005851.4079-5-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Huang Ying 5b7a1d4060 mm, hugetlbfs: rename address to haddr in hugetlb_cow()
To take better advantage of general huge page copying optimization, the
target subpage address will be passed to hugetlb_cow(), then
copy_user_huge_page().  So we will use both target subpage address and
huge page size aligned address in hugetlb_cow().  To distinguish between
them, "haddr" is used for huge page size aligned address to be
consistent with Transparent Huge Page naming convention.

Now, only huge page size aligned address is used in hugetlb_cow(), so
the "address" is renamed to "haddr" in hugetlb_cow() in this patch.
Next patch will use target subpage address in hugetlb_cow() too.

The patch is just code cleanup without any functionality changes.

Link: http://lkml.kernel.org/r/20180524005851.4079-4-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Huang Ying c9f4cd7138 mm, huge page: copy target sub-page last when copy huge page
Huge page helps to reduce TLB miss rate, but it has higher cache
footprint, sometimes this may cause some issue.  For example, when
copying huge page on x86_64 platform, the cache footprint is 4M.  But on
a Xeon E5 v3 2699 CPU, there are 18 cores, 36 threads, and only 45M LLC
(last level cache).  That is, in average, there are 2.5M LLC for each
core and 1.25M LLC for each thread.

If the cache contention is heavy when copying the huge page, and we copy
the huge page from the begin to the end, it is possible that the begin
of huge page is evicted from the cache after we finishing copying the
end of the huge page.  And it is possible for the application to access
the begin of the huge page after copying the huge page.

In c79b57e462 ("mm: hugetlb: clear target sub-page last when clearing
huge page"), to keep the cache lines of the target subpage hot, the
order to clear the subpages in the huge page in clear_huge_page() is
changed to clearing the subpage which is furthest from the target
subpage firstly, and the target subpage last.  The similar order
changing helps huge page copying too.  That is implemented in this
patch.  Because we have put the order algorithm into a separate
function, the implementation is quite simple.

The patch is a generic optimization which should benefit quite some
workloads, not for a specific use case.  To demonstrate the performance
benefit of the patch, we tested it with vm-scalability run on
transparent huge page.

With this patch, the throughput increases ~16.6% in vm-scalability
anon-cow-seq test case with 36 processes on a 2 socket Xeon E5 v3 2699
system (36 cores, 72 threads).  The test case set
/sys/kernel/mm/transparent_hugepage/enabled to be always, mmap() a big
anonymous memory area and populate it, then forked 36 child processes,
each writes to the anonymous memory area from the begin to the end, so
cause copy on write.  For each child process, other child processes
could be seen as other workloads which generate heavy cache pressure.
At the same time, the IPC (instruction per cycle) increased from 0.63 to
0.78, and the time spent in user space is reduced ~7.2%.

Link: http://lkml.kernel.org/r/20180524005851.4079-3-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Christopher Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Huang Ying c6ddfb6c58 mm, clear_huge_page: move order algorithm into a separate function
Patch series "mm, huge page: Copy target sub-page last when copy huge
page", v2.

Huge page helps to reduce TLB miss rate, but it has higher cache
footprint, sometimes this may cause some issue.  For example, when
copying huge page on x86_64 platform, the cache footprint is 4M.  But on
a Xeon E5 v3 2699 CPU, there are 18 cores, 36 threads, and only 45M LLC
(last level cache).  That is, in average, there are 2.5M LLC for each
core and 1.25M LLC for each thread.

If the cache contention is heavy when copying the huge page, and we copy
the huge page from the begin to the end, it is possible that the begin
of huge page is evicted from the cache after we finishing copying the
end of the huge page.  And it is possible for the application to access
the begin of the huge page after copying the huge page.

In c79b57e462 ("mm: hugetlb: clear target sub-page last when clearing
huge page"), to keep the cache lines of the target subpage hot, the
order to clear the subpages in the huge page in clear_huge_page() is
changed to clearing the subpage which is furthest from the target
subpage firstly, and the target subpage last.  The similar order
changing helps huge page copying too.  That is implemented in this
patchset.

The patchset is a generic optimization which should benefit quite some
workloads, not for a specific use case.  To demonstrate the performance
benefit of the patchset, we have tested it with vm-scalability run on
transparent huge page.

With this patchset, the throughput increases ~16.6% in vm-scalability
anon-cow-seq test case with 36 processes on a 2 socket Xeon E5 v3 2699
system (36 cores, 72 threads).  The test case set
/sys/kernel/mm/transparent_hugepage/enabled to be always, mmap() a big
anonymous memory area and populate it, then forked 36 child processes,
each writes to the anonymous memory area from the begin to the end, so
cause copy on write.  For each child process, other child processes
could be seen as other workloads which generate heavy cache pressure.
At the same time, the IPC (instruction per cycle) increased from 0.63 to
0.78, and the time spent in user space is reduced ~7.2%.

This patch (of 4):

In c79b57e462 ("mm: hugetlb: clear target sub-page last when clearing
huge page"), to keep the cache lines of the target subpage hot, the
order to clear the subpages in the huge page in clear_huge_page() is
changed to clearing the subpage which is furthest from the target
subpage firstly, and the target subpage last.  This optimization could
be applied to copying huge page too with the same order algorithm.  To
avoid code duplication and reduce maintenance overhead, in this patch,
the order algorithm is moved out of clear_huge_page() into a separate
function: process_huge_page().  So that we can use it for copying huge
page too.

This will change the direct calls to clear_user_highpage() into the
indirect calls.  But with the proper inline support of the compilers,
the indirect call will be optimized to be the direct call.  Our tests
show no performance change with the patch.

This patch is a code cleanup without functionality change.

Link: http://lkml.kernel.org/r/20180524005851.4079-2-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Christopher Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:29 -07:00
Yang Shi 87aa752906 mm: thp: inc counter for collapsed shmem THP
/sys/kernel/mm/transparent_hugepage/khugepaged/pages_collapsed is used
to record the counter of collapsed THP, but it just gets inc'ed in
anonymous THP collapse path, do this for shmem THP collapse too.

Link: http://lkml.kernel.org/r/1529622949-75504-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Yang Shi c2231020ea mm: thp: register mm for khugepaged when merging vma for shmem
When merging anonymous page vma, if the size of the vma can fit in at
least one hugepage, the mm will be registered for khugepaged for
collapsing THP in the future.

But it skips shmem vmas.  Do so for shmem also, but not for file-private
mappings when merging a vma in order to increase the odds of collapsing
a hugepage via khugepaged.

hugepage_vma_check() sounds like a good fit to do the check.  And move
the definition of it before khugepaged_enter_vma_merge() to avoid a
build error.

Link: http://lkml.kernel.org/r/1529697791-6950-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Jia-Ju Bai 8cded8668e mm/mempool.c: remove unused argument in kasan_unpoison_element() and remove_element()
The argument "gfp_t flags" is not used in kasan_unpoison_element() and
remove_element(), so remove it.

Link: http://lkml.kernel.org/r/20180621070332.16633-1-baijiaju1990@gmail.com
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Greg Thelen bb451fdf3d mm/vmscan.c: condense scan_control
Use smaller scan_control fields for order, priority, and reclaim_idx.
Convert fields from int => s8.  All easily fit within a byte:

 - allocation order range: 0..MAX_ORDER(64?)
 - priority range:         0..12(DEF_PRIORITY)
 - reclaim_idx range:      0..6(__MAX_NR_ZONES)

Since 6538b8ea88 ("x86_64: expand kernel stack to 16K") x86_64 stack
overflows are not an issue.  But it's inefficient to use ints.

Use s8 (signed byte) rather than u8 to allow for loops like:
	do {
		...
	} while (--sc.priority >= 0);

Add BUILD_BUG_ON to verify that s8 is capable of storing max values.

This reduces sizeof(struct scan_control):
 - 96 => 80 bytes (x86_64)
 - 68 => 56 bytes (i386)

scan_control structure field order is changed to utilize padding.  After
this patch there is 1 bit of scan_control padding.

akpm: makes my vmscan.o's .text 572 bytes smaller as well.

Link: http://lkml.kernel.org/r/20180530061212.84915-1-gthelen@google.com
Signed-off-by: Greg Thelen <gthelen@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Kirill A. Shutemov 10ed634152 mm/page_ext.c: constify lookup_page_ext() argument
lookup_page_ext() finds 'struct page_ext' for a given page.  It requires
only read access to the given struct page.

Current implemnentation takes 'struct page *' as an argument.  It makes
compiler complain when 'const struct page *' passed.

Change the argument to 'const struct page *'.

Link: http://lkml.kernel.org/r/20180531135457.20167-3-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Arnd Bergmann 46c9a946d7 shmem: use monotonic time for i_generation
get_seconds() is deprecated because it will lead to a 32-bit overflow in
2038 or 2106.  We don't need the i_generation to be strictly monotonic
anyway, and other file systems like ext4 and xfs just use prandom_u32(),
so let's use the same one here.

If this is considered too slow, we could also use ktime_get_seconds() or
ktime_get_real_seconds() to keep the previous behavior.  Both of these
return a time64_t and are not deprecated, but only return a unique value
once per second, and are predictable.

Link: http://lkml.kernel.org/r/20180620082556.581543-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Vlastimil Babka d6a24df006 mm, page_alloc: actually ignore mempolicies for high priority allocations
__alloc_pages_slowpath() has for a long time contained code to ignore
node restrictions from memory policies for high priority allocations.
The current code that resets the zonelist iterator however does
effectively nothing after commit 7810e6781e ("mm, page_alloc: do not
break __GFP_THISNODE by zonelist reset") removed a buggy zonelist reset.
Even before that commit, mempolicy restrictions were still not ignored,
as they are passed in ac->nodemask which is untouched by the code.

We can either remove the code, or make it work as intended.  Since
ac->nodemask can be set from task's mempolicy via alloc_pages_current()
and thus also alloc_pages(), it may indeed affect kernel allocations,
and it makes sense to ignore it to allow progress for high priority
allocations.

Thus, this patch resets ac->nodemask to NULL in such cases.  This
assumes all callers can handle it (i.e.  there are no guarantees as in
the case of __GFP_THISNODE) which seems to be the case.  The same
assumption is already present in check_retry_cpuset() for some time.

The expected effect is that high priority kernel allocations in the
context of userspace tasks (e.g.  OOM victims) restricted by mempolicies
will have higher chance to succeed if they are restricted to nodes with
depleted memory, while there are other nodes with free memory left.

It's not a new intention, but for the first time the code will match the
intention, AFAICS.  It was intended by commit 183f6371aa ("mm: ignore
mempolicies when using ALLOC_NO_WATERMARK") in v3.6 but I think it never
really worked, as mempolicy restriction was already encoded in nodemask,
not zonelist, at that time.

So originally that was for ALLOC_NO_WATERMARK only.  Then it was
adjusted by e46e7b77c9 ("mm, page_alloc: recalculate the preferred
zoneref if the context can ignore memory policies") and cd04ae1e2d
("mm, oom: do not rely on TIF_MEMDIE for memory reserves access") to the
current state.  So even GFP_ATOMIC would now ignore mempolicies after
the initial attempts fail - if the code worked as people thought it
does.

Link: http://lkml.kernel.org/r/20180612122624.8045-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Yang Shi fadae29530 thp: use mm_file_counter to determine update which rss counter
Since commit eca56ff906 ("mm, shmem: add internal shmem resident
memory accounting"), MM_SHMEMPAGES is added to separate the shmem
accounting from regular files.  So, all shmem pages should be accounted
to MM_SHMEMPAGES instead of MM_FILEPAGES.

And, normal 4K shmem pages have been accounted to MM_SHMEMPAGES, so
shmem thp pages should be not treated differently.  Account them to
MM_SHMEMPAGES via mm_counter_file() since shmem pages are swap backed to
keep consistent with normal 4K shmem pages.

This will not change the rss counter of processes since shmem pages are
still a part of it.

The /proc/pid/status and /proc/pid/statm counters will however be more
accurate wrt shmem usage, as originally intended.  And as eca56ff906
("mm, shmem: add internal shmem resident memory accounting") mentioned,
oom also could report more accurate "shmem-rss".

Link: http://lkml.kernel.org/r/1529442518-17398-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Pavel Tatashin 720e14ebec mm: skip invalid pages block at a time in zero_resv_unresv()
The role of zero_resv_unavail() is to make sure that every struct page
that is allocated but is not backed by memory that is accessible by
kernel is zeroed and not in some uninitialized state.

Since struct pages are allocated in blocks (2M pages in x86 case), we
can skip pageblock_nr_pages at a time, when the first one is found to be
invalid.

This optimization may help since now on x86 every hole in e820 maps is
marked as reserved in memblock, and thus will go through this function.

This function is called before sched_clock() is initialized, so I used
my x86 early boot clock patches to measure the performance improvement.

With 1T hole on i7-8700 currently we would take 0.606918s of boot time,
but with this optimization 0.001103s.

Link: http://lkml.kernel.org/r/20180615155733.1175-1-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Souptick Joarder 50a7ca3c6f mm: convert return type of handle_mm_fault() caller to vm_fault_t
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f422059 ("mm: change return type to vm_fault_t")

In this patch all the caller of handle_mm_fault() are changed to return
vm_fault_t type.

Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Vlastimil Babka 0882ff9190 mm, slub: restore the original intention of prefetch_freepointer()
In SLUB, prefetch_freepointer() is used when allocating an object from
cache's freelist, to make sure the next object in the list is cache-hot,
since it's probable it will be allocated soon.

Commit 2482ddec67 ("mm: add SLUB free list pointer obfuscation") has
unintentionally changed the prefetch in a way where the prefetch is
turned to a real fetch, and only the next->next pointer is prefetched.
In case there is not a stream of allocations that would benefit from
prefetching, the extra real fetch might add a useless cache miss to the
allocation.  Restore the previous behavior.

Link: http://lkml.kernel.org/r/20180809085245.22448-1-vbabka@suse.cz
Fixes: 2482ddec67 ("mm: add SLUB free list pointer obfuscation")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Dave Jiang e1fb4a0864 dax: remove VM_MIXEDMAP for fsdax and device dax
This patch is reworked from an earlier patch that Dan has posted:
https://patchwork.kernel.org/patch/10131727/

VM_MIXEDMAP is used by dax to direct mm paths like vm_normal_page() that
the memory page it is dealing with is not typical memory from the linear
map.  The get_user_pages_fast() path, since it does not resolve the vma,
is already using {pte,pmd}_devmap() as a stand-in for VM_MIXEDMAP, so we
use that as a VM_MIXEDMAP replacement in some locations.  In the cases
where there is no pte to consult we fallback to using vma_is_dax() to
detect the VM_MIXEDMAP special case.

Now that we have explicit driver pfn_t-flag opt-in/opt-out for
get_user_pages() support for DAX we can stop setting VM_MIXEDMAP.  This
also means we no longer need to worry about safely manipulating vm_flags
in a future where we support dynamically changing the dax mode of a
file.

DAX should also now be supported with madvise_behavior(), vma_merge(),
and copy_page_range().

This patch has been tested against ndctl unit test.  It has also been
tested against xfstests commit: 625515d using fake pmem created by
memmap and no additional issues have been observed.

Link: http://lkml.kernel.org/r/152847720311.55924.16999195879201817653.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:27 -07:00
Linus Torvalds fa1b5d09d0 Consolidation of Kconfig files by Christoph Hellwig.
Move the source statements of arch-independent Kconfig files instead of
 duplicating the includes in every arch/$(SRCARCH)/Kconfig.
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Merge tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kconfig consolidation from Masahiro Yamada:
 "Consolidation of Kconfig files by Christoph Hellwig.

  Move the source statements of arch-independent Kconfig files instead
  of duplicating the includes in every arch/$(SRCARCH)/Kconfig"

* tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: add a Memory Management options" menu
  kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt
  kconfig: use a menu in arch/Kconfig to reduce clutter
  kconfig: include kernel/Kconfig.preempt from init/Kconfig
  Kconfig: consolidate the "Kernel hacking" menu
  kconfig: include common Kconfig files from top-level Kconfig
  kconfig: remove duplicate SWAP symbol defintions
  um: create a proper drivers Kconfig
  um: cleanup Kconfig files
  um: stop abusing KBUILD_KCONFIG
2018-08-15 13:05:12 -07:00
Linus Torvalds 8c479c2c0f - drop unneeded Kconfig "select BUG" (Kamal Mostafa)
- add "hardened_usercopy=off" rare performance needs (Chris von Recklinghausen)
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Merge tag 'hardened-usercopy-v4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardened usercopy updates from Kees Cook:
 "This cleans up a minor Kconfig issue and adds a kernel boot option for
  disabling hardened usercopy for distro users that may have corner-case
  performance issues (e.g. high bandwidth small-packet UDP traffic).

  Summary:

   - drop unneeded Kconfig "select BUG" (Kamal Mostafa)

   - add "hardened_usercopy=off" rare performance needs (Chris von
     Recklinghausen)"

* tag 'hardened-usercopy-v4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  usercopy: Allow boot cmdline disabling of hardening
  usercopy: Do not select BUG with HARDENED_USERCOPY
2018-08-15 08:45:54 -07:00
Linus Torvalds e6ecec342f This was a moderately busy cycle for docs, with the usual collection of
small fixes and updates.  We also have new ktime_get_*() docs from Arnd,
 some kernel-doc fixes, a new set of Italian translations (non so se vale la
 pena, ma non fa male - speriamo bene), and some extensive early
 memory-management documentation improvements from Mike Rapoport.
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Merge tag 'docs-4.19' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "This was a moderately busy cycle for docs, with the usual collection
  of small fixes and updates.

  We also have new ktime_get_*() docs from Arnd, some kernel-doc fixes,
  a new set of Italian translations (non so se vale la pena, ma non fa
  male - speriamo bene), and some extensive early memory-management
  documentation improvements from Mike Rapoport"

* tag 'docs-4.19' of git://git.lwn.net/linux: (52 commits)
  Documentation: corrections to console/console.txt
  Documentation: add ioctl number entry for v4l2-subdev.h
  Remove gendered language from management style documentation
  scripts/kernel-doc: Escape all literal braces in regexes
  docs/mm: add description of boot time memory management
  docs/mm: memblock: add overview documentation
  docs/mm: memblock: add kernel-doc description for memblock types
  docs/mm: memblock: add kernel-doc comments for memblock_add[_node]
  docs/mm: memblock: update kernel-doc comments
  mm/memblock: add a name for memblock flags enumeration
  docs/mm: bootmem: add overview documentation
  docs/mm: bootmem: add kernel-doc description of 'struct bootmem_data'
  docs/mm: bootmem: fix kernel-doc warnings
  docs/mm: nobootmem: fixup kernel-doc comments
  mm/bootmem: drop duplicated kernel-doc comments
  Documentation: vm.txt: Adding 'nr_hugepages_mempolicy' parameter description.
  doc:it_IT: translation for kernel-hacking
  docs: Fix the reference labels in Locking.rst
  doc: tracing: Fix a typo of trace_stat
  mm: Introduce new type vm_fault_t
  ...
2018-08-14 14:29:31 -07:00
Linus Torvalds b018fc9800 Power management updates for 4.19-rc1
- Add a new framework for CPU idle time injection (Daniel Lezcano).
 
  - Add AVS support to the armada-37xx cpufreq driver (Gregory CLEMENT).
 
  - Add support for current CPU frequency reporting to the ACPI CPPC
    cpufreq driver (George Cherian).
 
  - Rework the cooling device registration in the imx6q/thermal
    driver (Bastian Stender).
 
  - Make the pcc-cpufreq driver refuse to work with dynamic
    scaling governors on systems with many CPUs to avoid
    scalability issues with it (Rafael Wysocki).
 
  - Fix the intel_pstate driver to report different maximum CPU
    frequencies on systems where they really are different and to
    ignore the turbo active ratio if hardware-managend P-states (HWP)
    are in use; make it use the match_string() helper (Xie Yisheng,
    Srinivas Pandruvada).
 
  - Fix a minor deferred probe issue in the qcom-kryo cpufreq
    driver (Niklas Cassel).
 
  - Add a tracepoint for the tracking of frequency limits changes
    (from Andriod) to the cpufreq core (Ruchi Kandoi).
 
  - Fix a circular lock dependency between CPU hotplug and sysfs
    locking in the cpufreq core reported by lockdep (Waiman Long).
 
  - Avoid excessive error reports on driver registration failures
    in the ARM cpuidle driver (Sudeep Holla).
 
  - Add a new device links flag to the driver core to make links go
    away automatically on supplier driver removal (Vivek Gautam).
 
  - Eliminate potential race condition between system-wide power
    management transitions and system shutdown (Pingfan Liu).
 
  - Add a quirk to save NVS memory on system suspend for the ASUS
    1025C laptop (Willy Tarreau).
 
  - Make more systems use suspend-to-idle (instead of ACPI S3) by
    default (Tristian Celestin).
 
  - Get rid of stack VLA usage in the low-level hibernation code on
    64-bit x86 (Kees Cook).
 
  - Fix error handling in the hibernation core and mark an expected
    fall-through switch in it (Chengguang Xu, Gustavo Silva).
 
  - Extend the generic power domains (genpd) framework to support
    attaching a device to a power domain by name (Ulf Hansson).
 
  - Fix device reference counting and user limits initialization in
    the devfreq core (Arvind Yadav, Matthias Kaehlcke).
 
  - Fix a few issues in the rk3399_dmc devfreq driver and improve its
    documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner).
 
  - Drop a redundant error message from the exynos-ppmu devfreq driver
    (Markus Elfring).
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Merge tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These add a new framework for CPU idle time injection, to be used by
  all of the idle injection code in the kernel in the future, fix some
  issues and add a number of relatively small extensions in multiple
  places.

  Specifics:

   - Add a new framework for CPU idle time injection (Daniel Lezcano).

   - Add AVS support to the armada-37xx cpufreq driver (Gregory
     CLEMENT).

   - Add support for current CPU frequency reporting to the ACPI CPPC
     cpufreq driver (George Cherian).

   - Rework the cooling device registration in the imx6q/thermal driver
     (Bastian Stender).

   - Make the pcc-cpufreq driver refuse to work with dynamic scaling
     governors on systems with many CPUs to avoid scalability issues
     with it (Rafael Wysocki).

   - Fix the intel_pstate driver to report different maximum CPU
     frequencies on systems where they really are different and to
     ignore the turbo active ratio if hardware-managend P-states (HWP)
     are in use; make it use the match_string() helper (Xie Yisheng,
     Srinivas Pandruvada).

   - Fix a minor deferred probe issue in the qcom-kryo cpufreq driver
     (Niklas Cassel).

   - Add a tracepoint for the tracking of frequency limits changes (from
     Andriod) to the cpufreq core (Ruchi Kandoi).

   - Fix a circular lock dependency between CPU hotplug and sysfs
     locking in the cpufreq core reported by lockdep (Waiman Long).

   - Avoid excessive error reports on driver registration failures in
     the ARM cpuidle driver (Sudeep Holla).

   - Add a new device links flag to the driver core to make links go
     away automatically on supplier driver removal (Vivek Gautam).

   - Eliminate potential race condition between system-wide power
     management transitions and system shutdown (Pingfan Liu).

   - Add a quirk to save NVS memory on system suspend for the ASUS 1025C
     laptop (Willy Tarreau).

   - Make more systems use suspend-to-idle (instead of ACPI S3) by
     default (Tristian Celestin).

   - Get rid of stack VLA usage in the low-level hibernation code on
     64-bit x86 (Kees Cook).

   - Fix error handling in the hibernation core and mark an expected
     fall-through switch in it (Chengguang Xu, Gustavo Silva).

   - Extend the generic power domains (genpd) framework to support
     attaching a device to a power domain by name (Ulf Hansson).

   - Fix device reference counting and user limits initialization in the
     devfreq core (Arvind Yadav, Matthias Kaehlcke).

   - Fix a few issues in the rk3399_dmc devfreq driver and improve its
     documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner).

   - Drop a redundant error message from the exynos-ppmu devfreq driver
     (Markus Elfring)"

* tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (35 commits)
  PM / reboot: Eliminate race between reboot and suspend
  PM / hibernate: Mark expected switch fall-through
  cpufreq: intel_pstate: Ignore turbo active ratio in HWP
  cpufreq: Fix a circular lock dependency problem
  cpu/hotplug: Add a cpus_read_trylock() function
  x86/power/hibernate_64: Remove VLA usage
  cpufreq: trace frequency limits change
  cpufreq: intel_pstate: Show different max frequency with turbo 3 and HWP
  cpufreq: pcc-cpufreq: Disable dynamic scaling on many-CPU systems
  cpufreq: qcom-kryo: Silently error out on EPROBE_DEFER
  cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC
  cpufreq: armada-37xx: Add AVS support
  dt-bindings: marvell: Add documentation for the Armada 3700 AVS binding
  PM / devfreq: rk3399_dmc: Fix duplicated opp table on reload.
  PM / devfreq: Init user limits from OPP limits, not viceversa
  PM / devfreq: rk3399_dmc: fix spelling mistakes.
  PM / devfreq: rk3399_dmc: do not print error when get supply and clk defer.
  dt-bindings: devfreq: rk3399_dmc: move interrupts to be optional.
  PM / devfreq: rk3399_dmc: remove wait for dcf irq event.
  dt-bindings: clock: add rk3399 DDR3 standard speed bins.
  ...
2018-08-14 13:12:24 -07:00
Linus Torvalds 73ba2fb33c for-4.19/block-20180812
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Merge tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "First pull request for this merge window, there will also be a
  followup request with some stragglers.

  This pull request contains:

   - Fix for a thundering heard issue in the wbt block code (Anchal
     Agarwal)

   - A few NVMe pull requests:
      * Improved tracepoints (Keith)
      * Larger inline data support for RDMA (Steve Wise)
      * RDMA setup/teardown fixes (Sagi)
      * Effects log suppor for NVMe target (Chaitanya Kulkarni)
      * Buffered IO suppor for NVMe target (Chaitanya Kulkarni)
      * TP4004 (ANA) support (Christoph)
      * Various NVMe fixes

   - Block io-latency controller support. Much needed support for
     properly containing block devices. (Josef)

   - Series improving how we handle sense information on the stack
     (Kees)

   - Lightnvm fixes and updates/improvements (Mathias/Javier et al)

   - Zoned device support for null_blk (Matias)

   - AIX partition fixes (Mauricio Faria de Oliveira)

   - DIF checksum code made generic (Max Gurtovoy)

   - Add support for discard in iostats (Michael Callahan / Tejun)

   - Set of updates for BFQ (Paolo)

   - Removal of async write support for bsg (Christoph)

   - Bio page dirtying and clone fixups (Christoph)

   - Set of bcache fix/changes (via Coly)

   - Series improving blk-mq queue setup/teardown speed (Ming)

   - Series improving merging performance on blk-mq (Ming)

   - Lots of other fixes and cleanups from a slew of folks"

* tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block: (190 commits)
  blkcg: Make blkg_root_lookup() work for queues in bypass mode
  bcache: fix error setting writeback_rate through sysfs interface
  null_blk: add lock drop/acquire annotation
  Blk-throttle: reduce tail io latency when iops limit is enforced
  block: paride: pd: mark expected switch fall-throughs
  block: Ensure that a request queue is dissociated from the cgroup controller
  block: Introduce blk_exit_queue()
  blkcg: Introduce blkg_root_lookup()
  block: Remove two superfluous #include directives
  blk-mq: count the hctx as active before allocating tag
  block: bvec_nr_vecs() returns value for wrong slab
  bcache: trivial - remove tailing backslash in macro BTREE_FLAG
  bcache: make the pr_err statement used for ENOENT only in sysfs_attatch section
  bcache: set max writeback rate when I/O request is idle
  bcache: add code comments for bset.c
  bcache: fix mistaken comments in request.c
  bcache: fix mistaken code comments in bcache.h
  bcache: add a comment in super.c
  bcache: avoid unncessary cache prefetch bch_btree_node_get()
  bcache: display rate debug parameters to 0 when writeback is not running
  ...
2018-08-14 10:23:25 -07:00
Linus Torvalds 958f338e96 Merge branch 'l1tf-final' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Merge L1 Terminal Fault fixes from Thomas Gleixner:
 "L1TF, aka L1 Terminal Fault, is yet another speculative hardware
  engineering trainwreck. It's a hardware vulnerability which allows
  unprivileged speculative access to data which is available in the
  Level 1 Data Cache when the page table entry controlling the virtual
  address, which is used for the access, has the Present bit cleared or
  other reserved bits set.

  If an instruction accesses a virtual address for which the relevant
  page table entry (PTE) has the Present bit cleared or other reserved
  bits set, then speculative execution ignores the invalid PTE and loads
  the referenced data if it is present in the Level 1 Data Cache, as if
  the page referenced by the address bits in the PTE was still present
  and accessible.

  While this is a purely speculative mechanism and the instruction will
  raise a page fault when it is retired eventually, the pure act of
  loading the data and making it available to other speculative
  instructions opens up the opportunity for side channel attacks to
  unprivileged malicious code, similar to the Meltdown attack.

  While Meltdown breaks the user space to kernel space protection, L1TF
  allows to attack any physical memory address in the system and the
  attack works across all protection domains. It allows an attack of SGX
  and also works from inside virtual machines because the speculation
  bypasses the extended page table (EPT) protection mechanism.

  The assoicated CVEs are: CVE-2018-3615, CVE-2018-3620, CVE-2018-3646

  The mitigations provided by this pull request include:

   - Host side protection by inverting the upper address bits of a non
     present page table entry so the entry points to uncacheable memory.

   - Hypervisor protection by flushing L1 Data Cache on VMENTER.

   - SMT (HyperThreading) control knobs, which allow to 'turn off' SMT
     by offlining the sibling CPU threads. The knobs are available on
     the kernel command line and at runtime via sysfs

   - Control knobs for the hypervisor mitigation, related to L1D flush
     and SMT control. The knobs are available on the kernel command line
     and at runtime via sysfs

   - Extensive documentation about L1TF including various degrees of
     mitigations.

  Thanks to all people who have contributed to this in various ways -
  patches, review, testing, backporting - and the fruitful, sometimes
  heated, but at the end constructive discussions.

  There is work in progress to provide other forms of mitigations, which
  might be less horrible performance wise for a particular kind of
  workloads, but this is not yet ready for consumption due to their
  complexity and limitations"

* 'l1tf-final' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits)
  x86/microcode: Allow late microcode loading with SMT disabled
  tools headers: Synchronise x86 cpufeatures.h for L1TF additions
  x86/mm/kmmio: Make the tracer robust against L1TF
  x86/mm/pat: Make set_memory_np() L1TF safe
  x86/speculation/l1tf: Make pmd/pud_mknotpresent() invert
  x86/speculation/l1tf: Invert all not present mappings
  cpu/hotplug: Fix SMT supported evaluation
  KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry
  x86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry
  x86/speculation: Simplify sysfs report of VMX L1TF vulnerability
  Documentation/l1tf: Remove Yonah processors from not vulnerable list
  x86/KVM/VMX: Don't set l1tf_flush_l1d from vmx_handle_external_intr()
  x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d
  x86: Don't include linux/irq.h from asm/hardirq.h
  x86/KVM/VMX: Introduce per-host-cpu analogue of l1tf_flush_l1d
  x86/irq: Demote irq_cpustat_t::__softirq_pending to u16
  x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush()
  x86/KVM/VMX: Replace 'vmx_l1d_flush_always' with 'vmx_l1d_flush_cond'
  x86/KVM/VMX: Don't set l1tf_flush_l1d to true from vmx_l1d_flush()
  cpu/hotplug: detect SMT disabled by BIOS
  ...
2018-08-14 09:46:06 -07:00
Rafael J. Wysocki 17bc3432e3 Merge branches 'pm-core', 'pm-domains', 'pm-sleep', 'acpi-pm' and 'pm-cpuidle'
Merge changes in the PM core, system-wide PM infrastructure, generic
power domains (genpd) framework, ACPI PM infrastructure and cpuidle
for 4.19.

* pm-core:
  driver core: Add flag to autoremove device link on supplier unbind
  driver core: Rename flag AUTOREMOVE to AUTOREMOVE_CONSUMER

* pm-domains:
  PM / Domains: Introduce dev_pm_domain_attach_by_name()
  PM / Domains: Introduce option to attach a device by name to genpd
  PM / Domains: dt: Add a power-domain-names property

* pm-sleep:
  PM / reboot: Eliminate race between reboot and suspend
  PM / hibernate: Mark expected switch fall-through
  x86/power/hibernate_64: Remove VLA usage
  PM / hibernate: cast PAGE_SIZE to int when comparing with error code

* acpi-pm:
  ACPI / PM: save NVS memory for ASUS 1025C laptop
  ACPI / PM: Default to s2idle in all machines supporting LP S0

* pm-cpuidle:
  ARM: cpuidle: silence error on driver registration failure
2018-08-14 09:48:10 +02:00
Linus Torvalds a66b4cd1e7 Merge branch 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs open-related updates from Al Viro:

 - "do we need fput() or put_filp()" rules are gone - it's always fput()
   now. We keep track of that state where it belongs - in ->f_mode.

 - int *opened mess killed - in finish_open(), in ->atomic_open()
   instances and in fs/namei.c code around do_last()/lookup_open()/atomic_open().

 - alloc_file() wrappers with saner calling conventions are introduced
   (alloc_file_clone() and alloc_file_pseudo()); callers converted, with
   much simplification.

 - while we are at it, saner calling conventions for path_init() and
   link_path_walk(), simplifying things inside fs/namei.c (both on
   open-related paths and elsewhere).

* 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
  few more cleanups of link_path_walk() callers
  allow link_path_walk() to take ERR_PTR()
  make path_init() unconditionally paired with terminate_walk()
  document alloc_file() changes
  make alloc_file() static
  do_shmat(): grab shp->shm_file earlier, switch to alloc_file_clone()
  new helper: alloc_file_clone()
  create_pipe_files(): switch the first allocation to alloc_file_pseudo()
  anon_inode_getfile(): switch to alloc_file_pseudo()
  hugetlb_file_setup(): switch to alloc_file_pseudo()
  ocxlflash_getfile(): switch to alloc_file_pseudo()
  cxl_getfile(): switch to alloc_file_pseudo()
  ... and switch shmem_file_setup() to alloc_file_pseudo()
  __shmem_file_setup(): reorder allocations
  new wrapper: alloc_file_pseudo()
  kill FILE_{CREATED,OPENED}
  switch atomic_open() and lookup_open() to returning 0 in all success cases
  document ->atomic_open() changes
  ->atomic_open(): return 0 in all success cases
  get rid of 'opened' in path_openat() and the helpers downstream
  ...
2018-08-13 19:58:36 -07:00
Linus Torvalds eac3411944 Merge branch 'x86/pti' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PTI updates from Thomas Gleixner:
 "The Speck brigade sadly provides yet another large set of patches
  destroying the perfomance which we carefully built and preserved

   - PTI support for 32bit PAE. The missing counter part to the 64bit
     PTI code implemented by Joerg.

   - A set of fixes for the Global Bit mechanics for non PCID CPUs which
     were setting the Global Bit too widely and therefore possibly
     exposing interesting memory needlessly.

   - Protection against userspace-userspace SpectreRSB

   - Support for the upcoming Enhanced IBRS mode, which is preferred
     over IBRS. Unfortunately we dont know the performance impact of
     this, but it's expected to be less horrible than the IBRS
     hammering.

   - Cleanups and simplifications"

* 'x86/pti' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  x86/mm/pti: Move user W+X check into pti_finalize()
  x86/relocs: Add __end_rodata_aligned to S_REL
  x86/mm/pti: Clone kernel-image on PTE level for 32 bit
  x86/mm/pti: Don't clear permissions in pti_clone_pmd()
  x86/mm/pti: Fix 32 bit PCID check
  x86/mm/init: Remove freed kernel image areas from alias mapping
  x86/mm/init: Add helper for freeing kernel image pages
  x86/mm/init: Pass unconverted symbol addresses to free_init_pages()
  mm: Allow non-direct-map arguments to free_reserved_area()
  x86/mm/pti: Clear Global bit more aggressively
  x86/speculation: Support Enhanced IBRS on future CPUs
  x86/speculation: Protect against userspace-userspace spectreRSB
  x86/kexec: Allocate 8k PGDs for PTI
  Revert "perf/core: Make sure the ring-buffer is mapped in all page-tables"
  x86/mm: Remove in_nmi() warning from vmalloc_fault()
  x86/entry/32: Check for VM86 mode in slow-path check
  perf/core: Make sure the ring-buffer is mapped in all page-tables
  x86/pti: Check the return value of pti_user_pagetable_walk_pmd()
  x86/pti: Check the return value of pti_user_pagetable_walk_p4d()
  x86/entry/32: Add debug code to check entry/exit CR3
  ...
2018-08-13 17:54:17 -07:00
Linus Torvalds 203b4fc903 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Thomas Gleixner:

 - Make lazy TLB mode even lazier to avoid pointless switch_mm()
   operations, which reduces CPU load by 1-2% for memcache workloads

 - Small cleanups and improvements all over the place

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Remove redundant check for kmem_cache_create()
  arm/asm/tlb.h: Fix build error implicit func declaration
  x86/mm/tlb: Make clear_asid_other() static
  x86/mm/tlb: Skip atomic operations for 'init_mm' in switch_mm_irqs_off()
  x86/mm/tlb: Always use lazy TLB mode
  x86/mm/tlb: Only send page table free TLB flush to lazy TLB CPUs
  x86/mm/tlb: Make lazy TLB mode lazier
  x86/mm/tlb: Restructure switch_mm_irqs_off()
  x86/mm/tlb: Leave lazy TLB mode at page table free time
  mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids
  x86/mm: Add TLB purge to free pmd/pte page interfaces
  ioremap: Update pgtable free interfaces with addr
  x86/mm: Disable ioremap free page handling on x86-PAE
2018-08-13 16:29:35 -07:00
jie@chenjie6@huwei.com 24eee1e4c4 mm/memory.c: check return value of ioremap_prot
ioremap_prot() can return NULL which could lead to an oops.

Link: http://lkml.kernel.org/r/1533195441-58594-1-git-send-email-chenjie6@huawei.com
Signed-off-by: chen jie <chenjie6@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: chenjie <chenjie6@huawei.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-10 20:19:58 -07:00
Pingfan Liu 55f2503c3b PM / reboot: Eliminate race between reboot and suspend
At present, "systemctl suspend" and "shutdown" can run in parrallel. A
system can suspend after devices_shutdown(), and resume. Then the shutdown
task goes on to power off. This causes many devices are not really shut
off. Hence replacing reboot_mutex with system_transition_mutex (renamed
from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as
system_transition_mutex can be better to reflect the purpose of the mutex.

Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-08-06 12:35:20 +02:00
Jens Axboe 05b9ba4b55 Linux 4.18-rc6
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Merge tag 'v4.18-rc6' into for-4.19/block2

Pull in 4.18-rc6 to get the NVMe core AEN change to avoid a
merge conflict down the line.

Signed-of-by: Jens Axboe <axboe@kernel.dk>
2018-08-05 19:32:09 -06:00
Dave Hansen 0d83432811 mm: Allow non-direct-map arguments to free_reserved_area()
free_reserved_area() takes pointers as arguments to show which addresses
should be freed.  However, it does this in a somewhat ambiguous way.  If it
gets a kernel direct map address, it always works.  However, if it gets an
address that is part of the kernel image alias mapping, it can fail.

It fails if all of the following happen:
 * The specified address is part of the kernel image alias
 * Poisoning is requested (forcing a memset())
 * The address is in a read-only portion of the kernel image

The memset() fails on the read-only mapping, of course.
free_reserved_area() *is* called both on the direct map and on kernel image
alias addresses.  We've just lucked out thus far that the kernel image
alias areas it gets used on are read-write.  I'm fairly sure this has been
just a happy accident.

It is quite easy to make free_reserved_area() work for all cases: just
convert the address to a direct map address before doing the memset(), and
do this unconditionally.  There is little chance of a regression here
because we previously did a virt_to_page() on the address for the memset,
so we know these are not highmem pages for which virt_to_page() would fail.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@google.com
Cc: aarcange@redhat.com
Cc: jgross@suse.com
Cc: jpoimboe@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: peterz@infradead.org
Cc: hughd@google.com
Cc: torvalds@linux-foundation.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: ak@linux.intel.com
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20180802225826.1287AE3E@viggo.jf.intel.com
2018-08-05 22:21:02 +02:00
Thomas Gleixner f2701b77bb Merge 4.18-rc7 into master to pick up the KVM dependcy
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-08-05 16:39:29 +02:00
Jane Chu eec3636ad1 ipc/shm.c add ->pagesize function to shm_vm_ops
Commit 05ea88608d ("mm, hugetlbfs: introduce ->pagesize() to
vm_operations_struct") adds a new ->pagesize() function to
hugetlb_vm_ops, intended to cover all hugetlbfs backed files.

With System V shared memory model, if "huge page" is specified, the
"shared memory" is backed by hugetlbfs files, but the mappings initiated
via shmget/shmat have their original vm_ops overwritten with shm_vm_ops,
so we need to add a ->pagesize function to shm_vm_ops.  Otherwise,
vma_kernel_pagesize() returns PAGE_SIZE given a hugetlbfs backed vma,
result in below BUG:

  fs/hugetlbfs/inode.c
        443             if (unlikely(page_mapped(page))) {
        444                     BUG_ON(truncate_op);

resulting in

  hugetlbfs: oracle (4592): Using mlock ulimits for SHM_HUGETLB is deprecated
  ------------[ cut here ]------------
  kernel BUG at fs/hugetlbfs/inode.c:444!
  Modules linked in: nfsv3 rpcsec_gss_krb5 nfsv4 ...
  CPU: 35 PID: 5583 Comm: oracle_5583_sbt Not tainted 4.14.35-1829.el7uek.x86_64 #2
  RIP: 0010:remove_inode_hugepages+0x3db/0x3e2
  ....
  Call Trace:
    hugetlbfs_evict_inode+0x1e/0x3e
    evict+0xdb/0x1af
    iput+0x1a2/0x1f7
    dentry_unlink_inode+0xc6/0xf0
    __dentry_kill+0xd8/0x18d
    dput+0x1b5/0x1ed
    __fput+0x18b/0x216
    ____fput+0xe/0x10
    task_work_run+0x90/0xa7
    exit_to_usermode_loop+0xdd/0x116
    do_syscall_64+0x187/0x1ae
    entry_SYSCALL_64_after_hwframe+0x150/0x0

[jane.chu@oracle.com: relocate comment]
  Link: http://lkml.kernel.org/r/20180731044831.26036-1-jane.chu@oracle.com
Link: http://lkml.kernel.org/r/20180727211727.5020-1-jane.chu@oracle.com
Fixes: 05ea88608d ("mm, hugetlbfs: introduce ->pagesize() to vm_operations_struct")
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-02 16:03:40 -07:00
Kirill Tkhai 7e97de0b03 memcg: remove memcg_cgroup::id from IDR on mem_cgroup_css_alloc() failure
In case of memcg_online_kmem() failure, memcg_cgroup::id remains hashed
in mem_cgroup_idr even after memcg memory is freed.  This leads to leak
of ID in mem_cgroup_idr.

This patch adds removal into mem_cgroup_css_alloc(), which fixes the
problem.  For better readability, it adds a generic helper which is used
in mem_cgroup_alloc() and mem_cgroup_id_put_many() as well.

Link: http://lkml.kernel.org/r/152354470916.22460.14397070748001974638.stgit@localhost.localdomain
Fixes 73f576c04b ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-02 16:03:40 -07:00
Mike Rapoport 3e039c5c0a docs/mm: memblock: add overview documentation
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-02 12:17:29 -06:00
Mike Rapoport 48a833cc74 docs/mm: memblock: add kernel-doc comments for memblock_add[_node]
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-02 12:17:28 -06:00
Mike Rapoport 47cec4432a docs/mm: memblock: update kernel-doc comments
* make memblock_discard description kernel-doc compatible
* add brief description for memblock_setclr_flag and describe its
  parameters
* fixup return value descriptions

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-02 12:17:28 -06:00
Mike Rapoport e1720fee27 mm/memblock: add a name for memblock flags enumeration
Since kernel-doc does not like anonymous enums the name is required for
adding documentation. While on it, I've also updated all the function
declarations to use 'enum memblock_flags' instead of unsigned long.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-02 12:17:27 -06:00
Mike Rapoport 58faef9328 docs/mm: bootmem: add overview documentation
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-02 12:17:27 -06:00
Mike Rapoport 7c757207fa docs/mm: bootmem: fix kernel-doc warnings
Add descriptions of the return value where they were missing and fixup the
syntax for present ones.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-02 12:17:27 -06:00
Mike Rapoport 8108ad51fe docs/mm: nobootmem: fixup kernel-doc comments
* add kernel-doc marking to free_bootmem_late() description
* add return value descriptions
* mention that address parameter of free_bootmem{_node} is a physical address

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-02 12:17:26 -06:00
Mike Rapoport 04c450603f mm/bootmem: drop duplicated kernel-doc comments
Parts of the bootmem interfaces are duplicated in nobootmem.c along with
the kernel-doc comments. There is no point to keep two copies of the
comments, so let's drop the bootmem.c copy.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-02 12:17:26 -06:00
Christoph Hellwig 59e0b520c7 kconfig: add a Memory Management options" menu
This moves all the options under a proper menu.

Based on a patch from Randy Dunlap.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-02 08:06:55 +09:00
Hugh Dickins 53406ed1bc mm: delete historical BUG from zap_pmd_range()
Delete the old VM_BUG_ON_VMA() from zap_pmd_range(), which asserted
that mmap_sem must be held when splitting an "anonymous" vma there.
Whether that's still strictly true nowadays is not entirely clear,
but the danger of sometimes crashing on the BUG is now fairly clear.

Even with the new stricter rules for anonymous vma marking, the
condition it checks for can possible trigger. Commit 44960f2a7b
("staging: ashmem: Fix SIGBUS crash when traversing mmaped ashmem
pages") is good, and originally I thought it was safe from that
VM_BUG_ON_VMA(), because the /dev/ashmem fd exposed to the user is
disconnected from the vm_file in the vma, and madvise(,,MADV_REMOVE)
insists on VM_SHARED.

But after I read John's earlier mail, drawing attention to the
vfs_fallocate() in there: I may be wrong, and I don't know if Android
has THP in the config anyway, but it looks to me like an
unmap_mapping_range() from ashmem's vfs_fallocate() could hit precisely
the VM_BUG_ON_VMA(), once it's vma_is_anonymous().

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-01 12:23:45 -07:00
Markus Stockhausen dc30b96ab6 readahead: stricter check for bdi io_pages
ondemand_readahead() checks bdi->io_pages to cap the maximum pages
that need to be processed. This works until the readit section. If
we would do an async only readahead (async size = sync size) and
target is at beginning of window we expand the pages by another
get_next_ra_size() pages. Btrace for large reads shows that kernel
always issues a doubled size read at the beginning of processing.
Add an additional check for io_pages in the lower part of the func.
The fix helps devices that hard limit bio pages and rely on proper
handling of max_hw_read_sectors (e.g. older FusionIO cards). For
that reason it could qualify for stable.

Fixes: 9491ae4a ("mm: don't cap request size based on read-ahead setting")
Cc: stable@vger.kernel.org
Signed-off-by: Markus Stockhausen stockhausen@collogia.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-27 09:09:53 -06:00
Li Wang 16e536ef47 zswap: re-check zswap_is_full() after do zswap_shrink()
/sys/../zswap/stored_pages keeps rising in a zswap test with
"zswap.max_pool_percent=0" parameter.  But it should not compress or
store pages any more since there is no space in the compressed pool.

Reproduce steps:
  1. Boot kernel with "zswap.enabled=1"
  2. Set the max_pool_percent to 0
      # echo 0 > /sys/module/zswap/parameters/max_pool_percent
  3. Do memory stress test to see if some pages have been compressed
      # stress --vm 1 --vm-bytes $mem_available"M" --timeout 60s
  4. Watching the 'stored_pages' number increasing or not

The root cause is:

  When zswap_max_pool_percent is set to 0 via kernel parameter,
  zswap_is_full() will always return true due to zswap_shrink().  But if
  the shinking is able to reclain a page successfully the code then
  proceeds to compressing/storing another page, so the value of
  stored_pages will keep changing.

To solve the issue, this patch adds a zswap_is_full() check again after
  zswap_shrink() to make sure it's now under the max_pool_percent, and to
  not compress/store if we reached the limit.

Link: http://lkml.kernel.org/r/20180530103936.17812-1-liwang@redhat.com
Signed-off-by: Li Wang <liwang@redhat.com>
Acked-by: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Huang Ying <huang.ying.caritas@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Kirill A. Shutemov bfd40eaff5 mm: fix vma_is_anonymous() false-positives
vma_is_anonymous() relies on ->vm_ops being NULL to detect anonymous
VMA.  This is unreliable as ->mmap may not set ->vm_ops.

False-positive vma_is_anonymous() may lead to crashes:

	next ffff8801ce5e7040 prev ffff8801d20eca50 mm ffff88019c1e13c0
	prot 27 anon_vma ffff88019680cdd8 vm_ops 0000000000000000
	pgoff 0 file ffff8801b2ec2d00 private_data 0000000000000000
	flags: 0xff(read|write|exec|shared|mayread|maywrite|mayexec|mayshare)
	------------[ cut here ]------------
	kernel BUG at mm/memory.c:1422!
	invalid opcode: 0000 [#1] SMP KASAN
	CPU: 0 PID: 18486 Comm: syz-executor3 Not tainted 4.18.0-rc3+ #136
	Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
	01/01/2011
	RIP: 0010:zap_pmd_range mm/memory.c:1421 [inline]
	RIP: 0010:zap_pud_range mm/memory.c:1466 [inline]
	RIP: 0010:zap_p4d_range mm/memory.c:1487 [inline]
	RIP: 0010:unmap_page_range+0x1c18/0x2220 mm/memory.c:1508
	Call Trace:
	 unmap_single_vma+0x1a0/0x310 mm/memory.c:1553
	 zap_page_range_single+0x3cc/0x580 mm/memory.c:1644
	 unmap_mapping_range_vma mm/memory.c:2792 [inline]
	 unmap_mapping_range_tree mm/memory.c:2813 [inline]
	 unmap_mapping_pages+0x3a7/0x5b0 mm/memory.c:2845
	 unmap_mapping_range+0x48/0x60 mm/memory.c:2880
	 truncate_pagecache+0x54/0x90 mm/truncate.c:800
	 truncate_setsize+0x70/0xb0 mm/truncate.c:826
	 simple_setattr+0xe9/0x110 fs/libfs.c:409
	 notify_change+0xf13/0x10f0 fs/attr.c:335
	 do_truncate+0x1ac/0x2b0 fs/open.c:63
	 do_sys_ftruncate+0x492/0x560 fs/open.c:205
	 __do_sys_ftruncate fs/open.c:215 [inline]
	 __se_sys_ftruncate fs/open.c:213 [inline]
	 __x64_sys_ftruncate+0x59/0x80 fs/open.c:213
	 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
	 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reproducer:

	#include <stdio.h>
	#include <stddef.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/ioctl.h>
	#include <sys/mman.h>
	#include <unistd.h>
	#include <fcntl.h>

	#define KCOV_INIT_TRACE			_IOR('c', 1, unsigned long)
	#define KCOV_ENABLE			_IO('c', 100)
	#define KCOV_DISABLE			_IO('c', 101)
	#define COVER_SIZE			(1024<<10)

	#define KCOV_TRACE_PC  0
	#define KCOV_TRACE_CMP 1

	int main(int argc, char **argv)
	{
		int fd;
		unsigned long *cover;

		system("mount -t debugfs none /sys/kernel/debug");
		fd = open("/sys/kernel/debug/kcov", O_RDWR);
		ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE);
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
		munmap(cover, COVER_SIZE * sizeof(unsigned long));
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
		memset(cover, 0, COVER_SIZE * sizeof(unsigned long));
		ftruncate(fd, 3UL << 20);
		return 0;
	}

This can be fixed by assigning anonymous VMAs own vm_ops and not relying
on it being NULL.

If ->mmap() failed to set ->vm_ops, mmap_region() will set it to
dummy_vm_ops.  This way we will have non-NULL ->vm_ops for all VMAs.

Link: http://lkml.kernel.org/r/20180724121139.62570-4-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: syzbot+3f84280d52be9b7083cc@syzkaller.appspotmail.com
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Kirill A. Shutemov 2c4541e24c mm: use vma_init() to initialize VMAs on stack and data segments
Make sure to initialize all VMAs properly, not only those which come
from vm_area_cachep.

Link: http://lkml.kernel.org/r/20180724121139.62570-3-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Dan Williams 6100e34b25 mm, memory_failure: Teach memory_failure() about dev_pagemap pages
mce: Uncorrected hardware memory error in user-access at af34214200
    {1}[Hardware Error]: It has been corrected by h/w and requires no further action
    mce: [Hardware Error]: Machine check events logged
    {1}[Hardware Error]: event severity: corrected
    Memory failure: 0xaf34214: reserved kernel page still referenced by 1 users
    [..]
    Memory failure: 0xaf34214: recovery action for reserved kernel page: Failed
    mce: Memory error not recovered

In contrast to typical memory, dev_pagemap pages may be dax mapped. With
dax there is no possibility to map in another page dynamically since dax
establishes 1:1 physical address to file offset associations. Also
dev_pagemap pages associated with NVDIMM / persistent memory devices can
internal remap/repair addresses with poison. While memory_failure()
assumes that it can discard typical poisoned pages and keep them
unmapped indefinitely, dev_pagemap pages may be returned to service
after the error is cleared.

Teach memory_failure() to detect and handle MEMORY_DEVICE_HOST
dev_pagemap pages that have poison consumed by userspace. Mark the
memory as UC instead of unmapping it completely to allow ongoing access
via the device driver (nd_pmem). Later, nd_pmem will grow support for
marking the page back to WB when the error is cleared.

Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-23 10:38:06 -07:00
Dan Williams ae1139ece1 mm, memory_failure: Collect mapping size in collect_procs()
In preparation for supporting memory_failure() for dax mappings, teach
collect_procs() to also determine the mapping size. Unlike typical
mappings the dax mapping size is determined by walking page-table
entries rather than using the compound-page accounting for THP pages.

Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-23 10:38:05 -07:00
Dan Williams 23e7b5c2e2 mm, madvise_inject_error: Let memory_failure() optionally take a page reference
The madvise_inject_error() routine uses get_user_pages() to lookup the
pfn and other information for injected error, but it does not release
that pin. The assumption is that failed pages should be taken out of
circulation.

However, for dax mappings it is not possible to take pages out of
circulation since they are 1:1 physically mapped as filesystem blocks,
or device-dax capacity. They also typically represent persistent memory
which has an error clearing capability.

In preparation for adding a special handler for dax mappings, shift the
responsibility of taking the page reference to memory_failure(). I.e.
drop the page reference and do not specify MF_COUNT_INCREASED to
memory_failure().

Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-23 10:38:05 -07:00
Dan Williams 2fa147bdbf mm, dev_pagemap: Do not clear ->mapping on final put
MEMORY_DEVICE_FS_DAX relies on typical page semantics whereby ->mapping
is only ever cleared by truncation, not final put.

Without this fix dax pages may forget their mapping association at the
end of every page pin event.

Move this atypical behavior that HMM wants into the HMM ->page_free()
callback.

Cc: <stable@vger.kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Fixes: d2c997c0f1 ("fs, dax: use page->mapping...")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-23 10:37:39 -07:00
Linus Torvalds 490fc05386 mm: make vm_area_alloc() initialize core fields
Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.

The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 15:24:03 -07:00
Linus Torvalds 95faf6992d mm: make vm_area_dup() actually copy the old vma data
.. and re-initialize th eanon_vma_chain head.

This removes some boiler-plate from the users, and also makes it clear
why it didn't need use the 'zalloc()' version.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 14:48:45 -07:00
Linus Torvalds 3928d4f5ee mm: use helper functions for allocating and freeing vm_area structs
The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.

We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.

Right now those functions are literally just wrappers around the
kmem_cache_*() calls.  This is a purely mechanical conversion:

    # new vma:
    kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()

    # copy old vma
    kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)

    # free vma
    kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)

to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 13:48:51 -07:00
Jing Xia 9f15bde671 mm: memcg: fix use after free in mem_cgroup_iter()
It was reported that a kernel crash happened in mem_cgroup_iter(), which
can be triggered if the legacy cgroup-v1 non-hierarchical mode is used.

Unable to handle kernel paging request at virtual address 6b6b6b6b6b6b8f
......
Call trace:
  mem_cgroup_iter+0x2e0/0x6d4
  shrink_zone+0x8c/0x324
  balance_pgdat+0x450/0x640
  kswapd+0x130/0x4b8
  kthread+0xe8/0xfc
  ret_from_fork+0x10/0x20

  mem_cgroup_iter():
      ......
      if (css_tryget(css))    <-- crash here
	    break;
      ......

The crashing reason is that mem_cgroup_iter() uses the memcg object whose
pointer is stored in iter->position, which has been freed before and
filled with POISON_FREE(0x6b).

And the root cause of the use-after-free issue is that
invalidate_reclaim_iterators() fails to reset the value of iter->position
to NULL when the css of the memcg is released in non- hierarchical mode.

Link: http://lkml.kernel.org/r/1531994807-25639-1-git-send-email-jing.xia@unisoc.com
Fixes: 6df38689e0 ("mm: memcontrol: fix possible memcg leak due to interrupted reclaim")
Signed-off-by: Jing Xia <jing.xia.mail@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <chunyan.zhang@unisoc.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 12:50:46 -07:00
Hugh Dickins e1f1b1572e mm/huge_memory.c: fix data loss when splitting a file pmd
__split_huge_pmd_locked() must check if the cleared huge pmd was dirty,
and propagate that to PageDirty: otherwise, data may be lost when a huge
tmpfs page is modified then split then reclaimed.

How has this taken so long to be noticed?  Because there was no problem
when the huge page is written by a write system call (shmem_write_end()
calls set_page_dirty()), nor when the page is allocated for a write fault
(fault_dirty_shared_page() calls set_page_dirty()); but when allocated for
a read fault (which MAP_POPULATE simulates), no set_page_dirty().

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1807111741430.1106@eggly.anvils
Fixes: d21b9e57c7 ("thp: handle file pages in split_huge_pmd()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Ashwin Chaugule <ashwinch@google.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: <stable@vger.kernel.org>	[4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 12:50:46 -07:00
Mathieu Malaterre 1937367205 mm/memblock: add missing include <linux/bootmem.h>
Commit 26f09e9b3a ("mm/memblock: add memblock memory allocation apis")
introduced two new function definitions:

  memblock_virt_alloc_try_nid_nopanic()
  memblock_virt_alloc_try_nid()

and commit ea1f5f3712 ("mm: define memblock_virt_alloc_try_nid_raw")
introduced the following function definition:

  memblock_virt_alloc_try_nid_raw()

This commit adds an include of header file <linux/bootmem.h> to provide
the missing function prototypes.  This silences the following gcc warning
(W=1):

  mm/memblock.c:1334:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_raw' [-Wmissing-prototypes]
  mm/memblock.c:1371:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_nopanic' [-Wmissing-prototypes]
  mm/memblock.c:1407:15: warning: no previous prototype for `memblock_virt_alloc_try_nid' [-Wmissing-prototypes]

Also adds #ifdef blockers to prevent compilation failure on mips/ia64
where CONFIG_NO_BOOTMEM=n as could be seen in commit commit 6cc22dc08a
("revert "mm/memblock: add missing include <linux/bootmem.h>"").

Because Makefile already does:

  obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o

The #ifdef has been simplified from:

  #if defined(CONFIG_HAVE_MEMBLOCK) && defined(CONFIG_NO_BOOTMEM)

to simply:

  #if defined(CONFIG_NO_BOOTMEM)

Link: http://lkml.kernel.org/r/20180626184422.24974-1-malat@debian.org
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Suggested-by: Tony Luck <tony.luck@intel.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 12:50:46 -07:00
Eric W. Biederman 40b3b02535 signal: Pass pid type into do_send_sig_info
This passes the information we already have at the call sight into
do_send_sig_info.  Ultimately allowing for better handling of signals
sent to a group of processes during fork.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 12:57:35 -05:00
Dan Williams 86a66810ba mm, madvise_inject_error: Disable MADV_SOFT_OFFLINE for ZONE_DEVICE pages
Given that dax / device-mapped pages are never subject to page
allocations remove them from consideration by the soft-offline
mechanism.

Reported-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-20 11:21:53 -07:00
Dan Williams 226ab56107 device-dax: Convert to vmf_insert_mixed and vm_fault_t
Use new return type vm_fault_t for fault and huge_fault handler. For
now, this is just documenting that the function returns a VM_FAULT value
rather than an errno.  Once all instances are converted, vm_fault_t will
become a distinct type.

Commit 1c8f422059 ("mm: change return type to vm_fault_t")

Previously vm_insert_mixed() returned an error code which driver mapped into
VM_FAULT_* type. The new function vmf_insert_mixed() will replace this
inefficiency by returning VM_FAULT_* type.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-20 11:19:15 -07:00
Rik van Riel 2ff6ddf19c x86/mm/tlb: Leave lazy TLB mode at page table free time
Andy discovered that speculative memory accesses while in lazy
TLB mode can crash a system, when a CPU tries to dereference a
speculative access using memory contents that used to be valid
page table memory, but have since been reused for something else
and point into la-la land.

The latter problem can be prevented in two ways. The first is to
always send a TLB shootdown IPI to CPUs in lazy TLB mode, while
the second one is to only send the TLB shootdown at page table
freeing time.

The second should result in fewer IPIs, since operationgs like
mprotect and madvise are very common with some workloads, but
do not involve page table freeing. Also, on munmap, batching
of page table freeing covers much larger ranges of virtual
memory than the batching of unmapped user pages.

Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: efault@gmx.de
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20180716190337.26133-3-riel@surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:35:31 +02:00
Rik van Riel c1a2f7f0c0 mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids
The mm_struct always contains a cpumask bitmap, regardless of
CONFIG_CPUMASK_OFFSTACK. That means the first step can be to
simplify things, and simply have one bitmask at the end of the
mm_struct for the mm_cpumask.

This does necessitate moving everything else in mm_struct into
an anonymous sub-structure, which can be randomized when struct
randomization is enabled.

The second step is to determine the correct size for the
mm_struct slab object from the size of the mm_struct
(excluding the CPU bitmap) and the size the cpumask.

For init_mm we can simply allocate the maximum size this
kernel is compiled for, since we only have one init_mm
in the system, anyway.

Pointer magic by Mike Galbraith, to evade -Wstringop-overflow
getting confused by the dynamically sized array.

Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20180716190337.26133-2-riel@surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:35:30 +02:00
Pavel Tatashin d1b47a7c9e mm: don't do zero_resv_unavail if memmap is not allocated
Moving zero_resv_unavail before memmap_init_zone(), caused a regression on
x86-32.

The cause is that we access struct pages before they are allocated when
CONFIG_FLAT_NODE_MEM_MAP is used.

free_area_init_nodes()
  zero_resv_unavail()
    mm_zero_struct_page(pfn_to_page(pfn)); <- struct page is not alloced
  free_area_init_node()
    if CONFIG_FLAT_NODE_MEM_MAP
      alloc_node_mem_map()
        memblock_virt_alloc_node_nopanic() <- struct page alloced here

On the other hand memblock_virt_alloc_node_nopanic() zeroes all the memory
that it returns, so we do not need to do zero_resv_unavail() here.

Fixes: e181ae0c5d ("mm: zero unavailable pages before memmap init")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Matt Hart <matt@mattface.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-16 09:41:57 -07:00
Linus Torvalds f353078f02 Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "11 fixes"

* emailed patches form Andrew Morton <akpm@linux-foundation.org>:
  reiserfs: fix buffer overflow with long warning messages
  checkpatch: fix duplicate invalid vsprintf pointer extension '%p<foo>' messages
  mm: do not bug_on on incorrect length in __mm_populate()
  mm/memblock.c: do not complain about top-down allocations for !MEMORY_HOTREMOVE
  fs, elf: make sure to page align bss in load_elf_library
  x86/purgatory: add missing FORCE to Makefile target
  net/9p/client.c: put refcount of trans_mod in error case in parse_opts()
  mm: allow arch to supply p??_free_tlb functions
  autofs: fix slab out of bounds read in getname_kernel()
  fs/proc/task_mmu.c: fix Locked field in /proc/pid/smaps*
  mm: do not drop unused pages when userfaultd is running
2018-07-14 11:14:33 -07:00
Michal Hocko bb177a732c mm: do not bug_on on incorrect length in __mm_populate()
syzbot has noticed that a specially crafted library can easily hit
VM_BUG_ON in __mm_populate

  kernel BUG at mm/gup.c:1242!
  invalid opcode: 0000 [#1] SMP
  CPU: 2 PID: 9667 Comm: a.out Not tainted 4.18.0-rc3 #644
  Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
  RIP: 0010:__mm_populate+0x1e2/0x1f0
  Code: 55 d0 65 48 33 14 25 28 00 00 00 89 d8 75 21 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 75 18 f1 ff 0f 0b e8 6e 18 f1 ff <0f> 0b 31 db eb c9 e8 93 06 e0 ff 0f 1f 00 55 48 89 e5 53 48 89 fb
  Call Trace:
     vm_brk_flags+0xc3/0x100
     vm_brk+0x1f/0x30
     load_elf_library+0x281/0x2e0
     __ia32_sys_uselib+0x170/0x1e0
     do_fast_syscall_32+0xca/0x420
     entry_SYSENTER_compat+0x70/0x7f

The reason is that the length of the new brk is not page aligned when we
try to populate the it.  There is no reason to bug on that though.
do_brk_flags already aligns the length properly so the mapping is
expanded as it should.  All we need is to tell mm_populate about it.
Besides that there is absolutely no reason to to bug_on in the first
place.  The worst thing that could happen is that the last page wouldn't
get populated and that is far from putting system into an inconsistent
state.

Fix the issue by moving the length sanitization code from do_brk_flags
up to vm_brk_flags.  The only other caller of do_brk_flags is brk
syscall entry and it makes sure to provide the proper length so t here
is no need for sanitation and so we can use do_brk_flags without it.

Also remove the bogus BUG_ONs.

[osalvador@techadventures.net: fix up vm_brk_flags s@request@len@]
Link: http://lkml.kernel.org/r/20180706090217.GI32658@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: syzbot <syzbot+5dcb560fe12aa5091c06@syzkaller.appspotmail.com>
Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-14 11:11:10 -07:00
Michal Hocko e3d301cae0 mm/memblock.c: do not complain about top-down allocations for !MEMORY_HOTREMOVE
Mike Rapoport is converting architectures from bootmem to nobootmem
allocator.  While doing so for m68k Geert has noticed that he gets a
scary looking warning:

  WARNING: CPU: 0 PID: 0 at mm/memblock.c:230
  memblock_find_in_range_node+0x11c/0x1be
  memblock: bottom-up allocation failed, memory hotunplug may be affected
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted
  4.18.0-rc3-atari-01343-gf2fb5f2e09a97a3c-dirty #7
  Call Trace: __warn+0xa8/0xc2
    kernel_pg_dir+0x0/0x1000
    netdev_lower_get_next+0x2/0x22
    warn_slowpath_fmt+0x2e/0x36
    memblock_find_in_range_node+0x11c/0x1be
    memblock_find_in_range_node+0x11c/0x1be
    memblock_find_in_range_node+0x0/0x1be
    vprintk_func+0x66/0x6e
    memblock_virt_alloc_internal+0xd0/0x156
    netdev_lower_get_next+0x2/0x22
    netdev_lower_get_next+0x2/0x22
    kernel_pg_dir+0x0/0x1000
    memblock_virt_alloc_try_nid_nopanic+0x58/0x7a
    netdev_lower_get_next+0x2/0x22
    kernel_pg_dir+0x0/0x1000
    kernel_pg_dir+0x0/0x1000
    EXPTBL+0x234/0x400
    EXPTBL+0x234/0x400
    alloc_node_mem_map+0x4a/0x66
    netdev_lower_get_next+0x2/0x22
    free_area_init_node+0xe2/0x29e
    EXPTBL+0x234/0x400
    paging_init+0x430/0x462
    kernel_pg_dir+0x0/0x1000
    printk+0x0/0x1a
    EXPTBL+0x234/0x400
    setup_arch+0x1b8/0x22c
    start_kernel+0x4a/0x40a
    _sinittext+0x344/0x9e8

The warning is basically saying that a top-down allocation can break
memory hotremove because memblock allocation is not movable.  But m68k
doesn't even support MEMORY_HOTREMOVE so there is no point to warn about
it.

Make the warning conditional only to configurations that care.

Link: http://lkml.kernel.org/r/20180706061750.GH32658@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Sam Creasey <sammy@sammy.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-14 11:11:10 -07:00
Christian Borntraeger bce73e4842 mm: do not drop unused pages when userfaultd is running
KVM guests on s390 can notify the host of unused pages.  This can result
in pte_unused callbacks to be true for KVM guest memory.

If a page is unused (checked with pte_unused) we might drop this page
instead of paging it.  This can have side-effects on userfaultd, when
the page in question was already migrated:

The next access of that page will trigger a fault and a user fault
instead of faulting in a new and empty zero page.  As QEMU does not
expect a userfault on an already migrated page this migration will fail.

The most straightforward solution is to ignore the pte_unused hint if a
userfault context is active for this VMA.

Link: http://lkml.kernel.org/r/20180703171854.63981-1-borntraeger@de.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-14 11:11:09 -07:00
Pavel Tatashin e181ae0c5d mm: zero unavailable pages before memmap init
We must zero struct pages for memory that is not backed by physical
memory, or kernel does not have access to.

Recently, there was a change which zeroed all memmap for all holes in
e820.  Unfortunately, it introduced a bug that is discussed here:

  https://www.spinics.net/lists/linux-mm/msg156764.html

Linus, also saw this bug on his machine, and confirmed that reverting
commit 124049decb ("x86/e820: put !E820_TYPE_RAM regions into
memblock.reserved") fixes the issue.

The problem is that we incorrectly zero some struct pages after they
were setup.

The fix is to zero unavailable struct pages prior to initializing of
struct pages.

A more detailed fix should come later that would avoid double zeroing
cases: one in __init_single_page(), the other one in
zero_resv_unavail().

Fixes: 124049decb ("x86/e820: put !E820_TYPE_RAM regions into memblock.reserved")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-14 11:02:20 -07:00
Al Viro 93dec2da7b ... and switch shmem_file_setup() to alloc_file_pseudo()
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:04:24 -04:00
Al Viro dac2d1f6cb __shmem_file_setup(): reorder allocations
grab inode and reserve memory first.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:04:24 -04:00
Al Viro c9c554f214 alloc_file(): switch to passing O_... flags instead of FMODE_... mode
... so that it could set both ->f_flags and ->f_mode, without callers
having to set ->f_flags manually.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:02:57 -04:00
Josef Bacik ca47e8c72a mm: skip readahead if the cgroup is congested
We noticed in testing we'd get pretty bad latency stalls under heavy
pressure because read ahead would try to do its thing while the cgroup
was under severe pressure.  If we're under this much pressure we want to
do as little IO as possible so we can still make progress on real work
if we're a throttled cgroup, so just skip readahead if our group is
under pressure.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09 09:07:54 -06:00
Tejun Heo 2cf855837b memcontrol: schedule throttling if we are congested
Memory allocations can induce swapping via kswapd or direct reclaim.  If
we are having IO done for us by kswapd and don't actually go into direct
reclaim we may never get scheduled for throttling.  So instead check to
see if our cgroup is congested, and if so schedule the throttling.
Before we return to user space the throttling stuff will only throttle
if we actually required it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09 09:07:54 -06:00
Tejun Heo 0d3bd88d54 swap,blkcg: issue swap io with the appropriate context
For backcharging we need to know who the page belongs to when swapping
it out.  We don't worry about things that do ->rw_page (zram etc) at the
moment, we're only worried about pages that actually go to a block
device.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09 09:07:54 -06:00
Josef Bacik 0d1e0c7cd5 blk: introduce REQ_SWAP
Just like REQ_META, it's important to know the IO coming down is swap
in order to guard against potential IO priority inversion issues with
cgroups.  Add REQ_SWAP and use it for all swap IO, and add it to our
bio_issue_as_root_blkg helper.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09 09:07:54 -06:00
Chris von Recklinghausen b5cb15d937 usercopy: Allow boot cmdline disabling of hardening
Enabling HARDENED_USERCOPY may cause measurable regressions in networking
performance: up to 8% under UDP flood.

I ran a small packet UDP flood using pktgen vs. a host b2b connected. On
the receiver side the UDP packets are processed by a simple user space
process that just reads and drops them:

https://github.com/netoptimizer/network-testing/blob/master/src/udp_sink.c

Not very useful from a functional PoV, but it helps to pin-point
bottlenecks in the networking stack.

When running a kernel with CONFIG_HARDENED_USERCOPY=y, I see a 5-8%
regression in the receive tput, compared to the same kernel without this
option enabled.

With CONFIG_HARDENED_USERCOPY=y, perf shows ~6% of CPU time spent
cumulatively in __check_object_size (~4%) and __virt_addr_valid (~2%).

The call-chain is:

__GI___libc_recvfrom
entry_SYSCALL_64_after_hwframe
do_syscall_64
__x64_sys_recvfrom
__sys_recvfrom
inet_recvmsg
udp_recvmsg
__check_object_size

udp_recvmsg() actually calls copy_to_iter() (inlined) and the latters
calls check_copy_size() (again, inlined).

A generic distro may want to enable HARDENED_USERCOPY in their default
kernel config, but at the same time, such distro may want to be able to
avoid the performance penalties in with the default configuration and
disable the stricter check on a per-boot basis.

This change adds a boot parameter that conditionally disables
HARDENED_USERCOPY via "hardened_usercopy=off".

Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-07-04 08:04:52 -07:00
Pavel Tatashin fc36def997 mm: teach dump_page() to correctly output poisoned struct pages
If struct page is poisoned, and uninitialized access is detected via
PF_POISONED_CHECK(page) dump_page() is called to output the page.  But,
the dump_page() itself accesses struct page to determine how to print
it, and therefore gets into a recursive loop.

For example:

  dump_page()
   __dump_page()
    PageSlab(page)
     PF_POISONED_CHECK(page)
      VM_BUG_ON_PGFLAGS(PagePoisoned(page), page)
       dump_page() recursion loop.

Link: http://lkml.kernel.org/r/20180702180536.2552-1-pasha.tatashin@oracle.com
Fixes: f165b378bb ("mm: uninitialized struct page poisoning sanity checking")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-03 17:32:19 -07:00
Zhen Lei 1e8e18f694 kasan: fix shadow_size calculation error in kasan_module_alloc
There is a special case that the size is "(N << KASAN_SHADOW_SCALE_SHIFT)
Pages plus X", the value of X is [1, KASAN_SHADOW_SCALE_SIZE-1].  The
operation "size >> KASAN_SHADOW_SCALE_SHIFT" will drop X, and the
roundup operation can not retrieve the missed one page.  For example:
size=0x28006, PAGE_SIZE=0x1000, KASAN_SHADOW_SCALE_SHIFT=3, we will get
shadow_size=0x5000, but actually we need 6 pages.

  shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT, PAGE_SIZE);

This can lead to a kernel crash when kasan is enabled and the value of
mod->core_layout.size or mod->init_layout.size is like above.  Because
the shadow memory of X has not been allocated and mapped.

move_module:
  ptr = module_alloc(mod->core_layout.size);
  ...
  memset(ptr, 0, mod->core_layout.size);		//crashed

  Unable to handle kernel paging request at virtual address ffff0fffff97b000
  ......
  Call trace:
    __asan_storeN+0x174/0x1a8
    memset+0x24/0x48
    layout_and_allocate+0xcd8/0x1800
    load_module+0x190/0x23e8
    SyS_finit_module+0x148/0x180

Link: http://lkml.kernel.org/r/1529659626-12660-1-git-send-email-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Dmitriy Vyukov <dvyukov@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Libin <huawei.libin@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-03 17:32:19 -07:00
Cannon Matthews 520495fe96 mm: hugetlb: yield when prepping struct pages
When booting with very large numbers of gigantic (i.e.  1G) pages, the
operations in the loop of gather_bootmem_prealloc, and specifically
prep_compound_gigantic_page, takes a very long time, and can cause a
softlockup if enough pages are requested at boot.

For example booting with 3844 1G pages requires prepping
(set_compound_head, init the count) over 1 billion 4K tail pages, which
takes considerable time.

Add a cond_resched() to the outer loop in gather_bootmem_prealloc() to
prevent this lockup.

Tested: Booted with softlockup_panic=1 hugepagesz=1G hugepages=3844 and
no softlockup is reported, and the hugepages are reported as
successfully setup.

Link: http://lkml.kernel.org/r/20180627214447.260804-1-cannonmatthews@google.com
Signed-off-by: Cannon Matthews <cannonmatthews@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-03 17:32:19 -07:00
Mikulas Patocka d50d82faa0 slub: fix failure when we delete and create a slab cache
In kernel 4.17 I removed some code from dm-bufio that did slab cache
merging (commit 21bb13276768: "dm bufio: remove code that merges slab
caches") - both slab and slub support merging caches with identical
attributes, so dm-bufio now just calls kmem_cache_create and relies on
implicit merging.

This uncovered a bug in the slub subsystem - if we delete a cache and
immediatelly create another cache with the same attributes, it fails
because of duplicate filename in /sys/kernel/slab/.  The slub subsystem
offloads freeing the cache to a workqueue - and if we create the new
cache before the workqueue runs, it complains because of duplicate
filename in sysfs.

This patch fixes the bug by moving the call of kobject_del from
sysfs_slab_remove_workfn to shutdown_cache.  kobject_del must be called
while we hold slab_mutex - so that the sysfs entry is deleted before a
cache with the same attributes could be created.

Running device-mapper-test-suite with:

  dmtest run --suite thin-provisioning -n /commit_failure_causes_fallback/

triggered:

  Buffer I/O error on dev dm-0, logical block 1572848, async page read
  device-mapper: thin: 253:1: metadata operation 'dm_pool_alloc_data_block' failed: error = -5
  device-mapper: thin: 253:1: aborting current metadata transaction
  sysfs: cannot create duplicate filename '/kernel/slab/:a-0000144'
  CPU: 2 PID: 1037 Comm: kworker/u48:1 Not tainted 4.17.0.snitm+ #25
  Hardware name: Supermicro SYS-1029P-WTR/X11DDW-L, BIOS 2.0a 12/06/2017
  Workqueue: dm-thin do_worker [dm_thin_pool]
  Call Trace:
   dump_stack+0x5a/0x73
   sysfs_warn_dup+0x58/0x70
   sysfs_create_dir_ns+0x77/0x80
   kobject_add_internal+0xba/0x2e0
   kobject_init_and_add+0x70/0xb0
   sysfs_slab_add+0xb1/0x250
   __kmem_cache_create+0x116/0x150
   create_cache+0xd9/0x1f0
   kmem_cache_create_usercopy+0x1c1/0x250
   kmem_cache_create+0x18/0x20
   dm_bufio_client_create+0x1ae/0x410 [dm_bufio]
   dm_block_manager_create+0x5e/0x90 [dm_persistent_data]
   __create_persistent_data_objects+0x38/0x940 [dm_thin_pool]
   dm_pool_abort_metadata+0x64/0x90 [dm_thin_pool]
   metadata_operation_failed+0x59/0x100 [dm_thin_pool]
   alloc_data_block.isra.53+0x86/0x180 [dm_thin_pool]
   process_cell+0x2a3/0x550 [dm_thin_pool]
   do_worker+0x28d/0x8f0 [dm_thin_pool]
   process_one_work+0x171/0x370
   worker_thread+0x49/0x3f0
   kthread+0xf8/0x130
   ret_from_fork+0x35/0x40
  kobject_add_internal failed for :a-0000144 with -EEXIST, don't try to register things with the same name in the same directory.
  kmem_cache_create(dm_bufio_buffer-16) failed with error -17

Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1806151817130.6333@file01.intranet.prod.int.rdu2.redhat.com
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-28 11:16:44 -07:00
Sebastian Andrzej Siewior 28557cc106 Revert mm/vmstat.c: fix vmstat_update() preemption BUG
Revert commit c7f26ccfb2 ("mm/vmstat.c: fix vmstat_update() preemption
BUG").  Steven saw a "using smp_processor_id() in preemptible" message
and added a preempt_disable() section around it to keep it quiet.  This
is not the right thing to do it does not fix the real problem.

vmstat_update() is invoked by a kworker on a specific CPU.  This worker
it bound to this CPU.  The name of the worker was "kworker/1:1" so it
should have been a worker which was bound to CPU1.  A worker which can
run on any CPU would have a `u' before the first digit.

smp_processor_id() can be used in a preempt-enabled region as long as
the task is bound to a single CPU which is the case here.  If it could
run on an arbitrary CPU then this is the problem we have an should seek
to resolve.

Not only this smp_processor_id() must not be migrated to another CPU but
also refresh_cpu_vm_stats() which might access wrong per-CPU variables.
Not to mention that other code relies on the fact that such a worker
runs on one specific CPU only.

Therefore revert that commit and we should look instead what broke the
affinity mask of the kworker.

Link: http://lkml.kernel.org/r/20180504104451.20278-1-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven J. Hill <steven.hill@cavium.com>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-28 11:16:44 -07:00
Linus Torvalds 77072ca59f for-linus-20180623
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Merge tag 'for-linus-20180623' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Further timeout fixes. We aren't quite there yet, so expect another
   round of fixes for that to completely close some of the IRQ vs
   completion races. (Christoph/Bart)

 - Set of NVMe fixes from the usual suspects, mostly error handling

 - Two off-by-one fixes (Dan)

 - Another bdi race fix (Jan)

 - Fix nbd reconfigure with NBD_DISCONNECT_ON_CLOSE (Doron)

* tag 'for-linus-20180623' of git://git.kernel.dk/linux-block:
  blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE
  bdi: Fix another oops in wb_workfn()
  lightnvm: Remove depends on HAS_DMA in case of platform dependency
  nvme-pci: limit max IO size and segments to avoid high order allocations
  nvme-pci: move nvme_kill_queues to nvme_remove_dead_ctrl
  nvme-fc: release io queues to allow fast fail
  nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag.
  block: sed-opal: Fix a couple off by one bugs
  blk-mq-debugfs: Off by one in blk_mq_rq_state_name()
  nvmet: reset keep alive timer in controller enable
  nvme-rdma: don't override opts->queue_size
  nvme-rdma: Fix command completion race at error recovery
  nvme-rdma: fix possible free of a non-allocated async event buffer
  nvme-rdma: fix possible double free condition when failing to create a controller
  Revert "block: Add warning for bi_next not NULL in bio_endio()"
  block: fix timeout changes for legacy request drivers
2018-06-24 06:33:54 +08:00
Jan Kara 3ee7e8697d bdi: Fix another oops in wb_workfn()
syzbot is reporting NULL pointer dereference at wb_workfn() [1] due to
wb->bdi->dev being NULL. And Dmitry confirmed that wb->state was
WB_shutting_down after wb->bdi->dev became NULL. This indicates that
unregister_bdi() failed to call wb_shutdown() on one of wb objects.

The problem is in cgwb_bdi_unregister() which does cgwb_kill() and thus
drops bdi's reference to wb structures before going through the list of
wbs again and calling wb_shutdown() on each of them. This way the loop
iterating through all wbs can easily miss a wb if that wb has already
passed through cgwb_remove_from_bdi_list() called from wb_shutdown()
from cgwb_release_workfn() and as a result fully shutdown bdi although
wb_workfn() for this wb structure is still running. In fact there are
also other ways cgwb_bdi_unregister() can race with
cgwb_release_workfn() leading e.g. to use-after-free issues:

CPU1                            CPU2
                                cgwb_bdi_unregister()
                                  cgwb_kill(*slot);

cgwb_release()
  queue_work(cgwb_release_wq, &wb->release_work);
cgwb_release_workfn()
                                  wb = list_first_entry(&bdi->wb_list, ...)
                                  spin_unlock_irq(&cgwb_lock);
  wb_shutdown(wb);
  ...
  kfree_rcu(wb, rcu);
                                  wb_shutdown(wb); -> oops use-after-free

We solve these issues by synchronizing writeback structure shutdown from
cgwb_bdi_unregister() with cgwb_release_workfn() using a new mutex. That
way we also no longer need synchronization using WB_shutting_down as the
mutex provides it for CONFIG_CGROUP_WRITEBACK case and without
CONFIG_CGROUP_WRITEBACK wb_shutdown() can be called only once from
bdi_unregister().

Reported-by: syzbot <syzbot+4a7438e774b21ddd8eca@syzkaller.appspotmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-22 12:08:07 -06:00
Andi Kleen 377eeaa8e1 x86/speculation/l1tf: Limit swap file size to MAX_PA/2
For the L1TF workaround its necessary to limit the swap file size to below
MAX_PA/2, so that the higher bits of the swap offset inverted never point
to valid memory.

Add a mechanism for the architecture to override the swap file size check
in swapfile.c and add a x86 specific max swapfile check function that
enforces that limit.

The check is only enabled if the CPU is vulnerable to L1TF.

In VMs with 42bit MAX_PA the typical limit is 2TB now, on a native system
with 46bit PA it is 32TB. The limit is only per individual swap file, so
it's always possible to exceed these limits with multiple swap files or
partitions.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
2018-06-20 19:10:01 +02:00
Andi Kleen 42e4089c78 x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings
For L1TF PROT_NONE mappings are protected by inverting the PFN in the page
table entry. This sets the high bits in the CPU's address space, thus
making sure to point to not point an unmapped entry to valid cached memory.

Some server system BIOSes put the MMIO mappings high up in the physical
address space. If such an high mapping was mapped to unprivileged users
they could attack low memory by setting such a mapping to PROT_NONE. This
could happen through a special device driver which is not access
protected. Normal /dev/mem is of course access protected.

To avoid this forbid PROT_NONE mappings or mprotect for high MMIO mappings.

Valid page mappings are allowed because the system is then unsafe anyways.

It's not expected that users commonly use PROT_NONE on MMIO. But to
minimize any impact this is only enforced if the mapping actually refers to
a high MMIO address (defined as the MAX_PA-1 bit being set), and also skip
the check for root.

For mmaps this is straight forward and can be handled in vm_insert_pfn and
in remap_pfn_range().

For mprotect it's a bit trickier. At the point where the actual PTEs are
accessed a lot of state has been changed and it would be difficult to undo
on an error. Since this is a uncommon case use a separate early page talk
walk pass for MMIO PROT_NONE mappings that checks for this condition
early. For non MMIO and non PROT_NONE there are no changes.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
2018-06-20 19:10:01 +02:00
Andrew Morton 6cc22dc08a revert "mm/memblock: add missing include <linux/bootmem.h>"
The patch fixed a W=1 warning but broke the ia64 build:

    CC      mm/memblock.o
  mm/memblock.c:1340: error: redefinition of `memblock_virt_alloc_try_nid_raw'
  ./include/linux/bootmem.h:335: error: previous definition of `memblock_virt_alloc_try_nid_raw' was here

Because inlcude/linux/bootmem.h says

	#if defined(CONFIG_HAVE_MEMBLOCK) && defined(CONFIG_NO_BOOTMEM)

whereas mm/Makefile says

	obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o

So revert 26f09e9b3a ("mm/memblock: add missing include
<linux/bootmem.h>") while a full fix can be worked on.

Fixes: 26f09e9b3a ("mm/memblock: add missing include <linux/bootmem.h>")
Reported-by: Tony Luck <tony.luck@gmail.com>
Cc: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-19 07:43:44 +09:00
Roman Gushchin fe6bdfc8e1 mm: fix oom_kill event handling
Commit e27be240df ("mm: memcg: make sure memory.events is uptodate
when waking pollers") converted most of memcg event counters to
per-memcg atomics, which made them less confusing for a user.  The
"oom_kill" counter remained untouched, so now it behaves differently
than other counters (including "oom").  This adds nothing but confusion.

Let's fix this by adding the MEMCG_OOM_KILL event, and follow the
MEMCG_OOM approach.

This also removes a hack from count_memcg_event_mm(), introduced earlier
specially for the OOM_KILL counter.

[akpm@linux-foundation.org: fix for droppage of memcg-replace-mm-owner-with-mm-memcg.patch]
Link: http://lkml.kernel.org/r/20180508124637.29984-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:25 +09:00
Joe Perches 0825a6f986 mm: use octal not symbolic permissions
mm/*.c files use symbolic and octal styles for permissions.

Using octal and not symbolic permissions is preferred by many as more
readable.

https://lkml.org/lkml/2016/8/2/1945

Prefer the direct use of octal for permissions.

Done using
$ scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace mm/*.c
and some typing.

Before:	 $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
44
After:	 $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
86

Miscellanea:

o Whitespace neatening around these conversions.

Link: http://lkml.kernel.org/r/2e032ef111eebcd4c5952bae86763b541d373469.1522102887.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:25 +09:00
Mel Gorman 37a4094e82 mremap: remove LATENCY_LIMIT from mremap to reduce the number of TLB shootdowns
Commit 5d1904204c ("mremap: fix race between mremap() and page
cleanning") fixed races between mremap and other operations for both
file-backed and anonymous mappings.  The file-backed was the most
critical as it allowed the possibility that data could be changed on a
physical page after page_mkclean returned which could trigger data loss
or data integrity issues.

A customer reported that the cost of the TLBs for anonymous regressions
was excessive and resulting in a 30-50% drop in performance overall
since this commit on a microbenchmark.  Unfortunately I neither have
access to the test-case nor can I describe what it does other than
saying that mremap operations dominate heavily.

This patch removes the LATENCY_LIMIT to handle TLB flushes on a PMD
boundary instead of every 64 pages to reduce the number of TLB
shootdowns by a factor of 8 in the ideal case.  LATENCY_LIMIT was almost
certainly used originally to limit the PTL hold times but the latency
savings are likely offset by the cost of IPIs in many cases.  This patch
is not reported to completely restore performance but gets it within an
acceptable percentage.  The given metric here is simply described as
"higher is better".

Baseline that was known good
002:  Metric:       91.05
004:  Metric:      109.45
008:  Metric:       73.08
016:  Metric:       58.14
032:  Metric:       61.09
064:  Metric:       57.76
128:  Metric:       55.43

Current
001:  Metric:       54.98
002:  Metric:       56.56
004:  Metric:       41.22
008:  Metric:       35.96
016:  Metric:       36.45
032:  Metric:       35.71
064:  Metric:       35.73
128:  Metric:       34.96

With patch
001:  Metric:       61.43
002:  Metric:       81.64
004:  Metric:       67.92
008:  Metric:       51.67
016:  Metric:       50.47
032:  Metric:       52.29
064:  Metric:       50.01
128:  Metric:       49.04

So for low threads, it's not restored but for larger number of threads,
it's closer to the "known good" baseline.

Using a different mremap-intensive workload that is not representative
of the real workload there is little difference observed outside of
noise in the headline metrics However, the TLB shootdowns are reduced by
11% on average and at the peak, TLB shootdowns were reduced by 21%.
Interrupts were sampled every second while the workload ran to get those
figures.  It's known that the figures will vary as the
non-representative load is non-deterministic.

An alternative patch was posted that should have significantly reduced
the TLB flushes but unfortunately it does not perform as well as this
version on the customer test case.  If revisited, the two patches can
stack on top of each other.

Link: http://lkml.kernel.org/r/20180606183803.k7qaw2xnbvzshv34@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:24 +09:00
Mathieu Malaterre 69b5086b12 mm/memblock: add missing include <linux/bootmem.h>
Commit 26f09e9b3a ("mm/memblock: add memblock memory allocation apis")
introduced two new function definitions:

  memblock_virt_alloc_try_nid_nopanic()
  memblock_virt_alloc_try_nid()

Commit ea1f5f3712 ("mm: define memblock_virt_alloc_try_nid_raw")
introduced the following function definition:

  memblock_virt_alloc_try_nid_raw()

This commit adds an includeof header file <linux/bootmem.h> to provide
the missing function prototypes.  Silence the following gcc warning
(W=1):

  mm/memblock.c:1334:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_raw' [-Wmissing-prototypes]
  mm/memblock.c:1371:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_nopanic' [-Wmissing-prototypes]
  mm/memblock.c:1407:15: warning: no previous prototype for `memblock_virt_alloc_try_nid' [-Wmissing-prototypes]

Link: http://lkml.kernel.org/r/20180606194144.16990-1-malat@debian.org
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:24 +09:00
Shakeel Butt 92ee383f6d mm: fix race between kmem_cache destroy, create and deactivate
The memcg kmem cache creation and deactivation (SLUB only) is
asynchronous.  If a root kmem cache is destroyed whose memcg cache is in
the process of creation or deactivation, the kernel may crash.

Example of one such crash:
	general protection fault: 0000 [#1] SMP PTI
	CPU: 1 PID: 1721 Comm: kworker/14:1 Not tainted 4.17.0-smp
	...
	Workqueue: memcg_kmem_cache kmemcg_deactivate_workfn
	RIP: 0010:has_cpu_slab
	...
	Call Trace:
	? on_each_cpu_cond
	__kmem_cache_shrink
	kmemcg_cache_deact_after_rcu
	kmemcg_deactivate_workfn
	process_one_work
	worker_thread
	kthread
	ret_from_fork+0x35/0x40

To fix this race, on root kmem cache destruction, mark the cache as
dying and flush the workqueue used for memcg kmem cache creation and
deactivation.  SLUB's memcg kmem cache deactivation also includes RCU
callback and thus make sure all previous registered RCU callbacks have
completed as well.

[shakeelb@google.com: handle the RCU callbacks for SLUB deactivation]
  Link: http://lkml.kernel.org/r/20180611192951.195727-1-shakeelb@google.com
[shakeelb@google.com: add more documentation, rename fields for readability]
  Link: http://lkml.kernel.org/r/20180522201336.196994-1-shakeelb@google.com
[akpm@linux-foundation.org: fix build, per Shakeel]
[shakeelb@google.com: v3.  Instead of refcount, flush the workqueue]
  Link: http://lkml.kernel.org/r/20180530001204.183758-1-shakeelb@google.com
Link: http://lkml.kernel.org/r/20180521174116.171846-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:23 +09:00
Daniel Jordan 955c97f085 mm/swapfile.c: fix swap_count comment about nonexistent SWAP_HAS_CONT
Commit 570a335b8e ("swap_info: swap count continuations") introduces
COUNT_CONTINUED but refers to it incorrectly as SWAP_HAS_CONT in a
comment in swap_count.  Fix it.

Link: http://lkml.kernel.org/r/20180612175919.30413-1-daniel.m.jordan@oracle.com
Fixes: 570a335b8e ("swap_info: swap count continuations")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:23 +09:00
Roman Gushchin df2a419677 mm: fix null pointer dereference in mem_cgroup_protected
Shakeel reported a crash in mem_cgroup_protected(), which can be triggered
by memcg reclaim if the legacy cgroup v1 use_hierarchy=0 mode is used:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000120
  PGD 8000001ff55da067 P4D 8000001ff55da067 PUD 1fdc7df067 PMD 0
  Oops: 0000 [#4] SMP PTI
  CPU: 0 PID: 15581 Comm: bash Tainted: G      D 4.17.0-smp-clean #5
  Hardware name: ...
  RIP: 0010:mem_cgroup_protected+0x54/0x130
  Code: 4c 8b 8e 00 01 00 00 4c 8b 86 08 01 00 00 48 8d 8a 08 ff ff ff 48 85 d2 ba 00 00 00 00 48 0f 44 ca 48 39 c8 0f 84 cf 00 00 00 <48> 8b 81 20 01 00 00 4d 89 ca 4c 39 c8 4c 0f 46 d0 4d 85 d2 74 05
  RSP: 0000:ffffabe64dfafa58 EFLAGS: 00010286
  RAX: ffff9fb6ff03d000 RBX: ffff9fb6f5b1b000 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffff9fb6f5b1b000 RDI: ffff9fb6f5b1b000
  RBP: ffffabe64dfafb08 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 000000000000c800 R12: ffffabe64dfafb88
  R13: ffff9fb6f5b1b000 R14: ffffabe64dfafb88 R15: ffff9fb77fffe000
  FS:  00007fed1f8ac700(0000) GS:ffff9fb6ff400000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000120 CR3: 0000001fdcf86003 CR4: 00000000001606f0
  Call Trace:
   ? shrink_node+0x194/0x510
   do_try_to_free_pages+0xfd/0x390
   try_to_free_mem_cgroup_pages+0x123/0x210
   try_charge+0x19e/0x700
   mem_cgroup_try_charge+0x10b/0x1a0
   wp_page_copy+0x134/0x5b0
   do_wp_page+0x90/0x460
   __handle_mm_fault+0x8e3/0xf30
   handle_mm_fault+0xfe/0x220
   __do_page_fault+0x262/0x500
   do_page_fault+0x28/0xd0
   ? page_fault+0x8/0x30
   page_fault+0x1e/0x30
  RIP: 0033:0x485b72

The problem happens because parent_mem_cgroup() returns a NULL pointer,
which is dereferenced later without a check.

As cgroup v1 has no memory guarantee support, let's make
mem_cgroup_protected() immediately return MEMCG_PROT_NONE, if the given
cgroup has no parent (non-hierarchical mode is used).

Link: http://lkml.kernel.org/r/20180611175418.7007-2-guro@fb.com
Fixes: bf8d5d52ff ("memcg: introduce memory.min")
Signed-off-by: Roman Gushchin <guro@fb.com>
Reported-by: Shakeel Butt <shakeelb@google.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Tested-by: John Stultz <john.stultz@linaro.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:23 +09:00
Jia He 1105a2fc02 mm/ksm.c: ignore STABLE_FLAG of rmap_item->address in rmap_walk_ksm()
In our armv8a server(QDF2400), I noticed lots of WARN_ON caused by
PAGE_SIZE unaligned for rmap_item->address under memory pressure
tests(start 20 guests and run memhog in the host).

  WARNING: CPU: 4 PID: 4641 at virt/kvm/arm/mmu.c:1826 kvm_age_hva_handler+0xc0/0xc8
  CPU: 4 PID: 4641 Comm: memhog Tainted: G        W 4.17.0-rc3+ #8
  Call trace:
   kvm_age_hva_handler+0xc0/0xc8
   handle_hva_to_gpa+0xa8/0xe0
   kvm_age_hva+0x4c/0xe8
   kvm_mmu_notifier_clear_flush_young+0x54/0x98
   __mmu_notifier_clear_flush_young+0x6c/0xa0
   page_referenced_one+0x154/0x1d8
   rmap_walk_ksm+0x12c/0x1d0
   rmap_walk+0x94/0xa0
   page_referenced+0x194/0x1b0
   shrink_page_list+0x674/0xc28
   shrink_inactive_list+0x26c/0x5b8
   shrink_node_memcg+0x35c/0x620
   shrink_node+0x100/0x430
   do_try_to_free_pages+0xe0/0x3a8
   try_to_free_pages+0xe4/0x230
   __alloc_pages_nodemask+0x564/0xdc0
   alloc_pages_vma+0x90/0x228
   do_anonymous_page+0xc8/0x4d0
   __handle_mm_fault+0x4a0/0x508
   handle_mm_fault+0xf8/0x1b0
   do_page_fault+0x218/0x4b8
   do_translation_fault+0x90/0xa0
   do_mem_abort+0x68/0xf0
   el0_da+0x24/0x28

In rmap_walk_ksm, the rmap_item->address might still have the
STABLE_FLAG, then the start and end in handle_hva_to_gpa might not be
PAGE_SIZE aligned.  Thus it will cause exceptions in handle_hva_to_gpa
on arm64.

This patch fixes it by ignoring (not removing) the low bits of address
when doing rmap_walk_ksm.

IMO, it should be backported to stable tree.  the storm of WARN_ONs is
very easy for me to reproduce.  More than that, I watched a panic (not
reproducible) as follows:

  page:ffff7fe003742d80 count:-4871 mapcount:-2126053375 mapping: (null) index:0x0
  flags: 0x1fffc00000000000()
  raw: 1fffc00000000000 0000000000000000 0000000000000000 ffffecf981470000
  raw: dead000000000100 dead000000000200 ffff8017c001c000 0000000000000000
  page dumped because: nonzero _refcount
  CPU: 29 PID: 18323 Comm: qemu-kvm Tainted: G W 4.14.15-5.hxt.aarch64 #1
  Hardware name: <snip for confidential issues>
  Call trace:
    dump_backtrace+0x0/0x22c
    show_stack+0x24/0x2c
    dump_stack+0x8c/0xb0
    bad_page+0xf4/0x154
    free_pages_check_bad+0x90/0x9c
    free_pcppages_bulk+0x464/0x518
    free_hot_cold_page+0x22c/0x300
    __put_page+0x54/0x60
    unmap_stage2_range+0x170/0x2b4
    kvm_unmap_hva_handler+0x30/0x40
    handle_hva_to_gpa+0xb0/0xec
    kvm_unmap_hva_range+0x5c/0xd0

I even injected a fault on purpose in kvm_unmap_hva_range by seting
size=size-0x200, the call trace is similar as above.  So I thought the
panic is similarly caused by the root cause of WARN_ON.

Andrea said:

: It looks a straightforward safe fix, on x86 hva_to_gfn_memslot would
: zap those bits and hide the misalignment caused by the low metadata
: bits being erroneously left set in the address, but the arm code
: notices when that's the last page in the memslot and the hva_end is
: getting aligned and the size is below one page.
:
: I think the problem triggers in the addr += PAGE_SIZE of
: unmap_stage2_ptes that never matches end because end is aligned but
: addr is not.
:
: 	} while (pte++, addr += PAGE_SIZE, addr != end);
:
: x86 again only works on hva_start/hva_end after converting it to
: gfn_start/end and that being in pfn units the bits are zapped before
: they risk to cause trouble.

Jia He said:

: I've tested by myself in arm64 server (QDF2400,46 cpus,96G mem) Without
: this patch, the WARN_ON is very easy for reproducing.  After this patch, I
: have run the same benchmarch for a whole day without any WARN_ONs

Link: http://lkml.kernel.org/r/1525403506-6750-1-git-send-email-hejianet@gmail.com
Signed-off-by: Jia He <jia.he@hxt-semitech.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Tested-by: Jia He <hejianet@gmail.com>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Cc: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:23 +09:00
Kees Cook 42bc47b353 treewide: Use array_size() in vmalloc()
The vmalloc() function has no 2-factor argument form, so multiplication
factors need to be wrapped in array_size(). This patch replaces cases of:

        vmalloc(a * b)

with:
        vmalloc(array_size(a, b))

as well as handling cases of:

        vmalloc(a * b * c)

with:

        vmalloc(array3_size(a, b, c))

This does, however, attempt to ignore constant size factors like:

        vmalloc(4 * 1024)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  vmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  vmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  vmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
  vmalloc(
-	sizeof(TYPE) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT_ID
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT_ID
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

  vmalloc(
-	SIZE * COUNT
+	array_size(COUNT, SIZE)
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  vmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  vmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  vmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  vmalloc(C1 * C2 * C3, ...)
|
  vmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants.
@@
expression E1, E2;
constant C1, C2;
@@

(
  vmalloc(C1 * C2, ...)
|
  vmalloc(
-	E1 * E2
+	array_size(E1, E2)
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Kees Cook 778e1cdd81 treewide: kvzalloc() -> kvcalloc()
The kvzalloc() function has a 2-factor argument form, kvcalloc(). This
patch replaces cases of:

        kvzalloc(a * b, gfp)

with:
        kvcalloc(a * b, gfp)

as well as handling cases of:

        kvzalloc(a * b * c, gfp)

with:

        kvzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kvcalloc(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kvzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kvzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kvzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kvzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kvzalloc
+ kvcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kvzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kvzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kvzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kvzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kvzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kvzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kvzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kvzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kvzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kvzalloc(C1 * C2 * C3, ...)
|
  kvzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kvzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kvzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kvzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kvzalloc(sizeof(THING) * C2, ...)
|
  kvzalloc(sizeof(TYPE) * C2, ...)
|
  kvzalloc(C1 * C2 * C3, ...)
|
  kvzalloc(C1 * C2, ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Kees Cook 6396bb2215 treewide: kzalloc() -> kcalloc()
The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

        kzalloc(a * b, gfp)

with:
        kcalloc(a * b, gfp)

as well as handling cases of:

        kzalloc(a * b * c, gfp)

with:

        kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kzalloc(sizeof(THING) * C2, ...)
|
  kzalloc(sizeof(TYPE) * C2, ...)
|
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Kees Cook 6da2ec5605 treewide: kmalloc() -> kmalloc_array()
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

        kmalloc(a * b, gfp)

with:
        kmalloc_array(a * b, gfp)

as well as handling cases of:

        kmalloc(a * b * c, gfp)

with:

        kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kmalloc(sizeof(THING) * C2, ...)
|
  kmalloc(sizeof(TYPE) * C2, ...)
|
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Linus Torvalds 7d3bf613e9 libnvdimm for 4.18
* DAX broke a fundamental assumption of truncate of file mapped pages.
   The truncate path assumed that it is safe to disconnect a pinned page
   from a file and let the filesystem reclaim the physical block. With DAX
   the page is equivalent to the filesystem block. Introduce
   dax_layout_busy_page() to enable filesystems to wait for pinned DAX
   pages to be released. Without this wait a filesystem could allocate
   blocks under active device-DMA to a new file.
 
 * DAX arranges for the block layer to be bypassed and uses
   dax_direct_access() + copy_to_iter() to satisfy read(2) calls.
   However, the memcpy_mcsafe() facility is available through the pmem
   block driver. In order to safely handle media errors, via the DAX
   block-layer bypass, introduce copy_to_iter_mcsafe().
 
 * Fix cache management policy relative to the ACPI NFIT Platform
   Capabilities Structure to properly elide cache flushes when they are not
   necessary. The table indicates whether CPU caches are power-fail
   protected. Clarify that a deep flush is always performed on
   REQ_{FUA,PREFLUSH} requests.
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Merge tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "This adds a user for the new 'bytes-remaining' updates to
  memcpy_mcsafe() that you already received through Ingo via the
  x86-dax- for-linus pull.

  Not included here, but still targeting this cycle, is support for
  handling memory media errors (poison) consumed via userspace dax
  mappings.

  Summary:

   - DAX broke a fundamental assumption of truncate of file mapped
     pages. The truncate path assumed that it is safe to disconnect a
     pinned page from a file and let the filesystem reclaim the physical
     block. With DAX the page is equivalent to the filesystem block.
     Introduce dax_layout_busy_page() to enable filesystems to wait for
     pinned DAX pages to be released. Without this wait a filesystem
     could allocate blocks under active device-DMA to a new file.

   - DAX arranges for the block layer to be bypassed and uses
     dax_direct_access() + copy_to_iter() to satisfy read(2) calls.
     However, the memcpy_mcsafe() facility is available through the pmem
     block driver. In order to safely handle media errors, via the DAX
     block-layer bypass, introduce copy_to_iter_mcsafe().

   - Fix cache management policy relative to the ACPI NFIT Platform
     Capabilities Structure to properly elide cache flushes when they
     are not necessary. The table indicates whether CPU caches are
     power-fail protected. Clarify that a deep flush is always performed
     on REQ_{FUA,PREFLUSH} requests"

* tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits)
  dax: Use dax_write_cache* helpers
  libnvdimm, pmem: Do not flush power-fail protected CPU caches
  libnvdimm, pmem: Unconditionally deep flush on *sync
  libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH
  acpi, nfit: Remove ecc_unit_size
  dax: dax_insert_mapping_entry always succeeds
  libnvdimm, e820: Register all pmem resources
  libnvdimm: Debug probe times
  linvdimm, pmem: Preserve read-only setting for pmem devices
  x86, nfit_test: Add unit test for memcpy_mcsafe()
  pmem: Switch to copy_to_iter_mcsafe()
  dax: Report bytes remaining in dax_iomap_actor()
  dax: Introduce a ->copy_to_iter dax operation
  uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation
  xfs, dax: introduce xfs_break_dax_layouts()
  xfs: prepare xfs_break_layouts() for another layout type
  xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL
  mm, fs, dax: handle layout changes to pinned dax mappings
  mm: fix __gup_device_huge vs unmap
  mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS
  ...
2018-06-08 17:21:52 -07:00
Dan Williams b56845794e Merge branch 'for-4.18/dax' into libnvdimm-for-next 2018-06-08 15:16:40 -07:00
Linus Torvalds 68abbe7295 Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - a few misc things

 - ocfs2 updates

 - v9fs updates

 - MM

 - procfs updates

 - lib/ updates

 - autofs updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
  autofs: small cleanup in autofs_getpath()
  autofs: clean up includes
  autofs: comment on selinux changes needed for module autoload
  autofs: update MAINTAINERS entry for autofs
  autofs: use autofs instead of autofs4 in documentation
  autofs: rename autofs documentation files
  autofs: create autofs Kconfig and Makefile
  autofs: delete fs/autofs4 source files
  autofs: update fs/autofs4/Makefile
  autofs: update fs/autofs4/Kconfig
  autofs: copy autofs4 to autofs
  autofs4: use autofs instead of autofs4 everywhere
  autofs4: merge auto_fs.h and auto_fs4.h
  fs/binfmt_misc.c: do not allow offset overflow
  checkpatch: improve patch recognition
  lib/ucs2_string.c: add MODULE_LICENSE()
  lib/mpi: headers cleanup
  lib/percpu_ida.c: use _irqsave() instead of local_irq_save() + spin_lock
  lib/idr.c: remove simple_ida_lock
  lib/bitmap.c: micro-optimization for __bitmap_complement()
  ...
2018-06-07 18:39:37 -07:00
Michal Hocko ce91f6ee5b mm: kvmalloc does not fallback to vmalloc for incompatible gfp flags
kvmalloc warned about incompatible gfp_mask to catch abusers (mostly
GFP_NOFS) with an intention that this will motivate authors of the code
to fix those.  Linus argues that this just motivates people to do even
more hacks like

	if (gfp == GFP_KERNEL)
		kvmalloc
	else
		kmalloc

I haven't seen this happening much (Linus pointed to bucket_lock special
cases an atomic allocation but my git foo hasn't found much more) but it
is true that we can grow those in future.  Therefore Linus suggested to
simply not fallback to vmalloc for incompatible gfp flags and rather
stick with the kmalloc path.

Link: http://lkml.kernel.org/r/20180601115329.27807-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Herbert <tom@quantonium.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:38 -07:00
Kirill A. Shutemov daa280753c mm/shmem.c: zero out unused vma fields in shmem_pseudo_vma_init()
shmem/tmpfs uses pseudo vma to allocate page with correct NUMA policy.

The pseudo vma doesn't have vm_page_prot set.  We are going to encode
encryption KeyID in vm_page_prot.  Having garbage there causes problems.

Zero out all unused fields in the pseudo vma.

Link: http://lkml.kernel.org/r/20180531135602.20321-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:38 -07:00
Vlastimil Babka 7810e6781e mm, page_alloc: do not break __GFP_THISNODE by zonelist reset
In __alloc_pages_slowpath() we reset zonelist and preferred_zoneref for
allocations that can ignore memory policies.  The zonelist is obtained
from current CPU's node.  This is a problem for __GFP_THISNODE
allocations that want to allocate on a different node, e.g.  because the
allocating thread has been migrated to a different CPU.

This has been observed to break SLAB in our 4.4-based kernel, because
there it relies on __GFP_THISNODE working as intended.  If a slab page
is put on wrong node's list, then further list manipulations may corrupt
the list because page_to_nid() is used to determine which node's
list_lock should be locked and thus we may take a wrong lock and race.

Current SLAB implementation seems to be immune by luck thanks to commit
511e3a0588 ("mm/slab: make cache_grow() handle the page allocated on
arbitrary node") but there may be others assuming that __GFP_THISNODE
works as promised.

We can fix it by simply removing the zonelist reset completely.  There
is actually no reason to reset it, because memory policies and cpusets
don't affect the zonelist choice in the first place.  This was different
when commit 183f6371aa ("mm: ignore mempolicies when using
ALLOC_NO_WATERMARK") introduced the code, as mempolicies provided their
own restricted zonelists.

We might consider this for 4.17 although I don't know if there's
anything currently broken.

SLAB is currently not affected, but in kernels older than 4.7 that don't
yet have 511e3a0588 ("mm/slab: make cache_grow() handle the page
allocated on arbitrary node") it is.  That's at least 4.4 LTS.  Older
ones I'll have to check.

So stable backports should be more important, but will have to be
reviewed carefully, as the code went through many changes.  BTW I think
that also the ac->preferred_zoneref reset is currently useless if we
don't also reset ac->nodemask from a mempolicy to NULL first (which we
probably should for the OOM victims etc?), but I would leave that for a
separate patch.

Link: http://lkml.kernel.org/r/20180525130853.13915-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Fixes: 183f6371aa ("mm: ignore mempolicies when using ALLOC_NO_WATERMARK")
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:38 -07:00
Mike Rapoport df2cc96e77 userfaultfd: prevent non-cooperative events vs mcopy_atomic races
If a process monitored with userfaultfd changes it's memory mappings or
forks() at the same time as uffd monitor fills the process memory with
UFFDIO_COPY, the actual creation of page table entries and copying of
the data in mcopy_atomic may happen either before of after the memory
mapping modifications and there is no way for the uffd monitor to
maintain consistent view of the process memory layout.

For instance, let's consider fork() running in parallel with
userfaultfd_copy():

process        		         |	uffd monitor
---------------------------------+------------------------------
fork()        		         | userfaultfd_copy()
...        		         | ...
    dup_mmap()        	         |     down_read(mmap_sem)
    down_write(mmap_sem)         |     /* create PTEs, copy data */
        dup_uffd()               |     up_read(mmap_sem)
        copy_page_range()        |
        up_write(mmap_sem)       |
        dup_uffd_complete()      |
            /* notify monitor */ |

If the userfaultfd_copy() takes the mmap_sem first, the new page(s) will
be present by the time copy_page_range() is called and they will appear
in the child's memory mappings.  However, if the fork() is the first to
take the mmap_sem, the new pages won't be mapped in the child's address
space.

If the pages are not present and child tries to access them, the monitor
will get page fault notification and everything is fine.  However, if
the pages *are present*, the child can access them without uffd
noticing.  And if we copy them into child it'll see the wrong data.
Since we are talking about background copy, we'd need to decide whether
the pages should be copied or not regardless #PF notifications.

Since userfaultfd monitor has no way to determine what was the order,
let's disallow userfaultfd_copy in parallel with the non-cooperative
events.  In such case we return -EAGAIN and the uffd monitor can
understand that userfaultfd_copy() clashed with a non-cooperative event
and take an appropriate action.

Link: http://lkml.kernel.org/r/1527061324-19949-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:38 -07:00
Tejun Heo be09102b41 mm: memcg: allow lowering memory.swap.max below the current usage
Currently an attempt to set swap.max into a value lower than the actual
swap usage fails, which causes configuration problems as there's no way
of lowering the configuration below the current usage short of turning
off swap entirely.  This makes swap.max difficult to use and allows
delegatees to lock the delegator out of reducing swap allocation.

This patch updates swap_max_write() so that the limit can be lowered
below the current usage.  It doesn't implement active reclaiming of swap
entries for the following reasons.

* mem_cgroup_swap_full() already tells the swap machinary to
  aggressively reclaim swap entries if the usage is above 50% of
  limit, so simply lowering the limit automatically triggers gradual
  reclaim.

* Forcing back swapped out pages is likely to heavily impact the
  workload and mess up the working set.  Given that swap usually is a
  lot less valuable and less scarce, letting the existing usage
  dissipate over time through the above gradual reclaim and as they're
  falted back in is likely the better behavior.

Link: http://lkml.kernel.org/r/20180523185041.GR1718769@devbig577.frc2.facebook.com
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Rik van Riel <riel@surriel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Souptick Joarder 20acce6799 mm/shmem.c: use new return type vm_fault_t
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

See commit 1c8f422059 ("mm: change return type to vm_fault_t")

vmf_error() is the newly introduce inline function in 4.17-rc6.

Link: http://lkml.kernel.org/r/20180521202410.GA17912@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Matthew Wilcox 325d7d4a96 slub: remove 'reserved' file from sysfs
Christoph doubts anyone was using the 'reserved' file in sysfs, so remove
it.

Link: http://lkml.kernel.org/r/20180518194519.3820-17-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Matthew Wilcox 9736d2a95e slub: remove kmem_cache->reserved
The reserved field was only used for embedding an rcu_head in the data
structure.  With the previous commit, we no longer need it.  That lets us
remove the 'reserved' argument to a lot of functions.

Link: http://lkml.kernel.org/r/20180518194519.3820-16-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Matthew Wilcox bf68c214df slab,slub: remove rcu_head size checks
rcu_head may now grow larger than list_head without affecting slab or
slub.

Link: http://lkml.kernel.org/r/20180518194519.3820-15-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Matthew Wilcox 4da1984edb mm: combine LRU and main union in struct page
This gives us five words of space in a single union in struct page.  The
compound_mapcount moves position (from offset 24 to offset 20) on 64-bit
systems, but that does not seem likely to cause any trouble.

Link: http://lkml.kernel.org/r/20180518194519.3820-11-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Matthew Wilcox b7ccc7f8c6 mm: move lru union within struct page
Since the LRU is two words, this does not affect the double-word alignment
of SLUB's freelist.

Link: http://lkml.kernel.org/r/20180518194519.3820-10-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Matthew Wilcox fa3015b7ee mm: use page->deferred_list
Now that we can represent the location of 'deferred_list' in C instead of
comments, make use of that ability.

Link: http://lkml.kernel.org/r/20180518194519.3820-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Matthew Wilcox 7d27a04bb2 mm: move 'private' union within struct page
By moving page->private to the fourth word of struct page, we can put the
SLUB counters in the same word as SLAB's s_mem and still do the
cmpxchg_double trick.  Now the SLUB counters no longer overlap with the
mapcount or refcount so we can drop the call to page_mapcount_reset() and
simplify set_page_slub_counters() to a single line.

Link: http://lkml.kernel.org/r/20180518194519.3820-6-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Matthew Wilcox d4fc5069a3 mm: switch s_mem and slab_cache in struct page
This will allow us to store slub's counters in the same bits as slab's
s_mem.  slub now needs to set page->mapping to NULL as it frees the page,
just like slab does.

Link: http://lkml.kernel.org/r/20180518194519.3820-5-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Matthew Wilcox 6e292b9be7 mm: split page_type out from _mapcount
We're already using a union of many fields here, so stop abusing the
_mapcount and make page_type its own field.  That implies renaming some of
the machinery that creates PageBuddy, PageBalloon and PageKmemcg; bring
back the PG_buddy, PG_balloon and PG_kmemcg names.

As suggested by Kirill, make page_type a bitmask.  Because it starts out
life as -1 (thanks to sharing the storage with _mapcount), setting a page
flag means clearing the appropriate bit.  This gives us space for probably
twenty or so extra bits (depending how paranoid we want to be about
_mapcount underflow).

Link: http://lkml.kernel.org/r/20180518194519.3820-3-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Huang Ying 285b8dcaac mm, hugetlbfs: pass fault address to no page handler
This is to take better advantage of general huge page clearing
optimization (commit c79b57e462b5: "mm: hugetlb: clear target sub-page
last when clearing huge page") for hugetlbfs.

In the general optimization patch, the sub-page to access will be
cleared last to avoid the cache lines of to access sub-page to be
evicted when clearing other sub-pages.  This works better if we have the
address of the sub-page to access, that is, the fault address inside the
huge page.  So the hugetlbfs no page fault handler is changed to pass
that information.  This will benefit workloads which don't access the
begin of the hugetlbfs huge page after the page fault under heavy cache
contention for shared last level cache.

The patch is a generic optimization which should benefit quite some
workloads, not for a specific use case.  To demonstrate the performance
benefit of the patch, we tested it with vm-scalability run on hugetlbfs.

With this patch, the throughput increases ~28.1% in vm-scalability
anon-w-seq test case with 88 processes on a 2 socket Xeon E5 2699 v4
system (44 cores, 88 threads).  The test case creates 88 processes, each
process mmaps a big anonymous memory area with MAP_HUGETLB and writes to
it from the end to the begin.  For each process, other processes could
be seen as other workload which generates heavy cache pressure.  At the
same time, the cache miss rate reduced from ~36.3% to ~25.6%, the IPC
(instruction per cycle) increased from 0.3 to 0.37, and the time spent
in user space is reduced ~19.3%.

Link: http://lkml.kernel.org/r/20180517083539.9242-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:36 -07:00
Souptick Joarder b3ec9f33ac mm: change return type to vm_fault_t
Use new return type vm_fault_t for fault handler in struct
vm_operations_struct.  For now, this is just documenting that the
function returns a VM_FAULT value rather than an errno.  Once all
instances are converted, vm_fault_t will become a distinct type.

See commit 1c8f422059 ("mm: change return type to vm_fault_t")

Link: http://lkml.kernel.org/r/20180512063745.GA26866@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:36 -07:00
Souptick Joarder 2bcd6454ba mm: use new return type vm_fault_t
Use new return type vm_fault_t for fault handler in struct
vm_operations_struct.  For now, this is just documenting that the
function returns a VM_FAULT value rather than an errno.  Once all
instances are converted, vm_fault_t will become a distinct type.

Link: http://lkml.kernel.org/r/20180511190542.GA2412@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:36 -07:00
Huaisheng Ye a380b40abb mm/page_alloc.c: remove useless parameter of finalise_ac()
finalise_ac() has parameter order which is not used at all.  Remove it.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:36 -07:00
Andy Shevchenko 3cadfa2b94 mm/vmpressure.c: convert to use match_string() helper
The new helper returns index of the matching string in an array.  We are
going to use it here.

Link: http://lkml.kernel.org/r/20180503203206.44046-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:36 -07:00