Commit Graph

7272 Commits

Author SHA1 Message Date
Joonsoo Kim
16025177e1 slab: remove kmem_bufctl_t
Now, we changed the management method of free objects of the slab and
there is no need to use special value, BUFCTL_END, BUFCTL_FREE and
BUFCTL_ACTIVE. So remove them.

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:34 +03:00
Joonsoo Kim
b1cb0982bd slab: change the management method of free objects of the slab
Current free objects management method of the slab is weird, because
it touch random position of the array of kmem_bufctl_t when we try to
get free object. See following example.

struct slab's free = 6
kmem_bufctl_t array: 1 END 5 7 0 4 3 2

To get free objects, we access this array with following pattern.
6 -> 3 -> 7 -> 2 -> 5 -> 4 -> 0 -> 1 -> END

If we have many objects, this array would be larger and be not in the same
cache line. It is not good for performance.

We can do same thing through more easy way, like as the stack.
Only thing we have to do is to maintain stack top to free object. I use
free field of struct slab for this purpose. After that, if we need to get
an object, we can get it at stack top and manipulate top pointer.
That's all. This method already used in array_cache management.
Following is an access pattern when we use this method.

struct slab's free = 0
kmem_bufctl_t array: 6 3 7 2 5 4 0 1

To get free objects, we access this array with following pattern.
0 -> 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7

This may help cache line footprint if slab has many objects, and,
in addition, this makes code much much simpler.

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:33 +03:00
Joonsoo Kim
a57a49887e slab: use __GFP_COMP flag for allocating slab pages
If we use 'struct page' of first page as 'struct slab', there is no
advantage not to use __GFP_COMP. So use __GFP_COMP flag for all the cases.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:33 +03:00
Joonsoo Kim
56f295ef0d slab: use well-defined macro, virt_to_slab()
This is trivial change, just use well-defined macro.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:32 +03:00
Joonsoo Kim
68126702b4 slab: overloading the RCU head over the LRU for RCU free
With build-time size checking, we can overload the RCU head over the LRU
of struct page to free pages of a slab in rcu context. This really help to
implement to overload the struct slab over the struct page and this
eventually reduce memory usage and cache footprint of the SLAB.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:31 +03:00
Joonsoo Kim
07d417a1c6 slab: remove cachep in struct slab_rcu
We can get cachep using page in struct slab_rcu, so remove it.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:29 +03:00
Joonsoo Kim
1ea991b00c slab: remove nodeid in struct slab
We can get nodeid using address translation, so this field is not useful.
Therefore, remove it.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:27 +03:00
Joonsoo Kim
ac2b54edbc slab: remove colouroff in struct slab
Now there is no user colouroff, so remove it.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:26 +03:00
Joonsoo Kim
0c3aa83e00 slab: change return type of kmem_getpages() to struct page
It is more understandable that kmem_getpages() return struct page.
And, with this, we can reduce one translation from virt addr to page and
makes better code than before. Below is a change of this patch.

* Before
   text	   data	    bss	    dec	    hex	filename
  22123	  23434	      4	  45561	   b1f9	mm/slab.o

* After
   text	   data	    bss	    dec	    hex	filename
  22074	  23434	      4	  45512	   b1c8	mm/slab.o

And this help following patch to remove struct slab's colouroff.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:23 +03:00
Joonsoo Kim
73293c2f90 slab: correct pfmemalloc check
We checked pfmemalloc by slab unit, not page unit. You can see this
in is_slab_pfmemalloc(). So other pages don't need to be set/cleared
pfmemalloc.

And, therefore we should check pfmemalloc in page flag of first page,
but current implementation don't do that. virt_to_head_page(obj) just
return 'struct page' of that object, not one of first page, since the SLAB
don't use __GFP_COMP when CONFIG_MMU. To get 'struct page' of first page,
we first get a slab and try to get it via virt_to_head_page(slab->s_mem).

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
2013-10-24 20:17:19 +03:00
Andrey Vagin
6f6b895189 memcg: check that kmem_cache has memcg_params before accessing it
If the system had a few memory groups and all of them were destroyed,
memcg_limited_groups_array_size has non-zero value, but all new caches
are created without memcg_params, because memcg_kmem_enabled() returns
false.

We try to enumirate child caches in a few places and all of them are
potentially dangerous.

For example my kernel is compiled with CONFIG_SLAB and it crashed when I
tryed to mount a NFS share after a few experiments with kmemcg.

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: [<ffffffff8118166a>] do_tune_cpucache+0x8a/0xd0
  PGD b942a067 PUD b999f067 PMD 0
  Oops: 0000 [#1] SMP
  Modules linked in: fscache(+) ip6table_filter ip6_tables iptable_filter ip_tables i2c_piix4 pcspkr virtio_net virtio_balloon i2c_core floppy
  CPU: 0 PID: 357 Comm: modprobe Not tainted 3.11.0-rc7+ #59
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff8800b9f98240 ti: ffff8800ba32e000 task.ti: ffff8800ba32e000
  RIP: 0010:[<ffffffff8118166a>]  [<ffffffff8118166a>] do_tune_cpucache+0x8a/0xd0
  RSP: 0018:ffff8800ba32fb70  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006
  RDX: 0000000000000000 RSI: ffff8800b9f98910 RDI: 0000000000000246
  RBP: ffff8800ba32fba0 R08: 0000000000000002 R09: 0000000000000004
  R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000010
  R13: 0000000000000008 R14: 00000000000000d0 R15: ffff8800375d0200
  FS:  00007f55f1378740(0000) GS:ffff8800bfa00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 00007f24feba57a0 CR3: 0000000037b51000 CR4: 00000000000006f0
  Call Trace:
    enable_cpucache+0x49/0x100
    setup_cpu_cache+0x215/0x280
    __kmem_cache_create+0x2fa/0x450
    kmem_cache_create_memcg+0x214/0x350
    kmem_cache_create+0x2b/0x30
    fscache_init+0x19b/0x230 [fscache]
    do_one_initcall+0xfa/0x1b0
    load_module+0x1c41/0x26d0
    SyS_finit_module+0x86/0xb0
    system_call_fastpath+0x16/0x1b

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-28 19:26:38 -07:00
Cyrill Gorcunov
6dec97dc92 mm: move_ptes -- Set soft dirty bit depending on pte type
Dave reported corrupted swap entries

 | [ 4588.541886] swap_free: Unused swap offset entry 00002d15
 | [ 4588.541952] BUG: Bad page map in process trinity-kid12  pte:005a2a80 pmd:22c01f067

and Hugh pointed that in move_ptes _PAGE_SOFT_DIRTY bit set regardless
the type of entry pte consists of.  The trick here is that when we carry
soft dirty status in swap entries we are to use _PAGE_SWP_SOFT_DIRTY
instead, because this is the only place in pte which can be used for own
needs without intersecting with bits owned by swap entry type/offset.

Reported-and-tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Analyzed-by: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-27 09:36:17 -07:00
Linus Torvalds
4d4323ea2d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Assorted fixes from the last week or so"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  VFS: collect_mounts() should return an ERR_PTR
  bfs: iget_locked() doesn't return an ERR_PTR
  efs: iget_locked() doesn't return an ERR_PTR()
  proc: kill the extra proc_readfd_common()->dir_emit_dots()
  cope with potentially long ->d_dname() output for shmem/hugetlb
2013-08-25 12:25:38 -07:00
Al Viro
118b230225 cope with potentially long ->d_dname() output for shmem/hugetlb
dynamic_dname() is both too much and too little for those - the
output may be well in excess of 64 bytes dynamic_dname() assumes
to be enough (thanks to ashmem feeding really long names to
shmem_file_setup()) and vsnprintf() is an overkill for those
guys.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-08-24 12:10:17 -04:00
Michal Hocko
07555ac144 memcg: get rid of swapaccount leftovers
The swapaccount kernel parameter without any values has been removed by
commit a2c8990aed ("memsw: remove noswapaccount kernel parameter") but
it seems that we didn't get rid of all the left overs.

Make sure that menuconfig help text and kernel-parameters.txt are clear
about value for the paramter and remove the stalled comment which is not
very much useful on its own.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Gergely Risko <gergely@risko.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-23 09:51:22 -07:00
Linus Torvalds
2b047252d0 Fix TLB gather virtual address range invalidation corner cases
Ben Tebulin reported:

 "Since v3.7.2 on two independent machines a very specific Git
  repository fails in 9/10 cases on git-fsck due to an SHA1/memory
  failures.  This only occurs on a very specific repository and can be
  reproduced stably on two independent laptops.  Git mailing list ran
  out of ideas and for me this looks like some very exotic kernel issue"

and bisected the failure to the backport of commit 53a59fc67f ("mm:
limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT").

That commit itself is not actually buggy, but what it does is to make it
much more likely to hit the partial TLB invalidation case, since it
introduces a new case in tlb_next_batch() that previously only ever
happened when running out of memory.

The real bug is that the TLB gather virtual memory range setup is subtly
buggered.  It was introduced in commit 597e1c3580 ("mm/mmu_gather:
enable tlb flush range in generic mmu_gather"), and the range handling
was already fixed at least once in commit e6c495a96c ("mm: fix the TLB
range flushed when __tlb_remove_page() runs out of slots"), but that fix
was not complete.

The problem with the TLB gather virtual address range is that it isn't
set up by the initial tlb_gather_mmu() initialization (which didn't get
the TLB range information), but it is set up ad-hoc later by the
functions that actually flush the TLB.  And so any such case that forgot
to update the TLB range entries would potentially miss TLB invalidates.

Rather than try to figure out exactly which particular ad-hoc range
setup was missing (I personally suspect it's the hugetlb case in
zap_huge_pmd(), which didn't have the same logic as zap_pte_range()
did), this patch just gets rid of the problem at the source: make the
TLB range information available to tlb_gather_mmu(), and initialize it
when initializing all the other tlb gather fields.

This makes the patch larger, but conceptually much simpler.  And the end
result is much more understandable; even if you want to play games with
partial ranges when invalidating the TLB contents in chunks, now the
range information is always there, and anybody who doesn't want to
bother with it won't introduce subtle bugs.

Ben verified that this fixes his problem.

Reported-bisected-and-tested-by: Ben Tebulin <tebulin@googlemail.com>
Build-testing-by: Stephen Rothwell <sfr@canb.auug.org.au>
Build-testing-by: Richard Weinberger <richard.weinberger@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-16 08:52:46 -07:00
Cyrill Gorcunov
41bb3476b3 mm: save soft-dirty bits on file pages
Andy reported that if file page get reclaimed we lose the soft-dirty bit
if it was there, so save _PAGE_BIT_SOFT_DIRTY bit when page address get
encoded into pte entry.  Thus when #pf happens on such non-present pte
we can restore it back.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13 17:57:48 -07:00
Cyrill Gorcunov
179ef71cbc mm: save soft-dirty bits on swapped pages
Andy Lutomirski reported that if a page with _PAGE_SOFT_DIRTY bit set
get swapped out, the bit is getting lost and no longer available when
pte read back.

To resolve this we introduce _PTE_SWP_SOFT_DIRTY bit which is saved in
pte entry for the page being swapped out.  When such page is to be read
back from a swap cache we check for bit presence and if it's there we
clear it and restore the former _PAGE_SOFT_DIRTY bit back.

One of the problem was to find a place in pte entry where we can save
the _PTE_SWP_SOFT_DIRTY bit while page is in swap.  The _PAGE_PSE was
chosen for that, it doesn't intersect with swap entry format stored in
pte.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13 17:57:47 -07:00
Andrey Vagin
3e6b11df24 memcg: don't initialize kmem-cache destroying work for root caches
struct memcg_cache_params has a union.  Different parts of this union
are used for root and non-root caches.  A part with destroying work is
used only for non-root caches.

I fixed the same problem in another place v3.9-rc1-16204-gf101a94, but
didn't notice this one.

This patch fixes the kernel panic:

[   46.848187] BUG: unable to handle kernel paging request at 000000fffffffeb8
[   46.849026] IP: [<ffffffff811a484c>] kmem_cache_destroy_memcg_children+0x6c/0xc0
[   46.849092] PGD 0
[   46.849092] Oops: 0000 [#1] SMP
...

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: <stable@vger.kernel.org>    [3.9.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13 17:57:47 -07:00
Linus Torvalds
370905069c Revert "slub: do not put a slab to cpu partial list when cpu_partial is 0"
This reverts commit 318df36e57.

This commit caused Steven Rostedt's hackbench runs to run out of memory
due to a leak.  As noted by Joonsoo Kim, it is buggy in the following
scenario:

 "I guess, you may set 0 to all kmem caches's cpu_partial via sysfs,
  doesn't it?

  In this case, memory leak is possible in following case.  Code flow of
  possible leak is follwing case.

   * in __slab_free()
   1. (!new.inuse || !prior) && !was_frozen
   2. !kmem_cache_debug && !prior
   3. new.frozen = 1
   4. after cmpxchg_double_slab, run the (!n) case with new.frozen=1
   5. with this patch, put_cpu_partial() doesn't do anything,
      because this cache's cpu_partial is 0
   6. return

  In step 5, leak occur"

And Steven does indeed have cpu_partial set to 0 due to RT testing.

Joonsoo is cooking up a patch, but everybody agrees that reverting this
for now is the right thing to do.

Reported-and-bisected-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-08 09:06:37 -07:00
Hugh Dickins
387aae6fdd tmpfs: fix SEEK_DATA/SEEK_HOLE regression
Commit 46a1c2c7ae ("vfs: export lseek_execute() to modules") broke the
tmpfs SEEK_DATA/SEEK_HOLE implementation, because vfs_setpos() converts
the carefully prepared -ENXIO to -EINVAL.  Other filesystems avoid it in
error cases: do the same in tmpfs.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-04 11:40:17 -07:00
Michal Hocko
33cb876e94 vmpressure: make sure there are no events queued after memcg is offlined
vmpressure is called synchronously from reclaim where the target_memcg
is guaranteed to be alive but the eventfd is signaled from the work
queue context.  This means that memcg (along with vmpressure structure
which is embedded into it) might go away while the work item is pending
which would result in use-after-release bug.

We have two possible ways how to fix this.  Either vmpressure pins memcg
before it schedules vmpr->work and unpin it in vmpressure_work_fn or
explicitely flush the work item from the css_offline context (as
suggested by Tejun).

This patch implements the later one and it introduces vmpressure_cleanup
which flushes the vmpressure work queue item item.  It hooks into
mem_cgroup_css_offline after the memcg itself is cleaned up.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Tejun Heo <tj@kernel.org>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Li Zefan <lizefan@huawei.com>
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>
2013-07-31 14:41:04 -07:00
Michal Hocko
8e0ed445b3 vmpressure: do not check for pending work to prevent from new work
because it is racy and it doesn't give us much anyway as schedule_work
handles this case already.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Tejun Heo <tj@kernel.org>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Li Zefan <lizefan@huawei.com>
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>
2013-07-31 14:41:04 -07:00
Michal Hocko
22f2020f84 vmpressure: change vmpressure::sr_lock to spinlock
There is nothing that can sleep inside critical sections protected by
this lock and those sections are really small so there doesn't make much
sense to use mutex for them.  Change the log to a spinlock

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Tejun Heo <tj@kernel.org>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Li Zefan <lizefan@huawei.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:03 -07:00
Heesub Shin
9d8c5b5284 mm: zbud: fix condition check on allocation size
zbud_alloc() incorrectly verifies the size of allocation limit.  It
should deny the allocation request greater than (PAGE_SIZE -
ZHDR_SIZE_ALIGNED - CHUNK_SIZE), not (PAGE_SIZE - ZHDR_SIZE_ALIGNED)
which has no remaining spaces for its buddy.  There is no point in
spending the entire zbud page storing only a single page, since we don't
have any benefits.

Signed-off-by: Heesub Shin <heesub.shin@samsung.com>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Dongjun Shin <d.j.shin@samsung.com>
Cc: Sunae Seo <sunae.seo@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:03 -07:00
Kirill A. Shutemov
e180cf806a thp, mm: avoid PageUnevictable on active/inactive lru lists
active/inactive lru lists can contain unevicable pages (i.e.  ramfs pages
that have been placed on the LRU lists when first allocated), but these
pages must not have PageUnevictable set - otherwise shrink_[in]active_list
goes crazy:

kernel BUG at /home/space/kas/git/public/linux-next/mm/vmscan.c:1122!

1090 static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
1091                 struct lruvec *lruvec, struct list_head *dst,
1092                 unsigned long *nr_scanned, struct scan_control *sc,
1093                 isolate_mode_t mode, enum lru_list lru)
1094 {
...
1108                 switch (__isolate_lru_page(page, mode)) {
1109                 case 0:
...
1116                 case -EBUSY:
...
1121                 default:
1122                         BUG();
1123                 }
1124         }
...
1130 }

__isolate_lru_page() returns EINVAL for PageUnevictable(page).

For lru_add_page_tail(), it means we should not set PageUnevictable()
for tail pages unless we're sure that it will go to LRU_UNEVICTABLE.
Let's just copy PG_active and PG_unevictable from head page in
__split_huge_page_refcount(), it will simplify lru_add_page_tail().

This will fix one more bug in lru_add_page_tail(): if
page_evictable(page_tail) is false and PageLRU(page) is true, page_tail
will go to the same lru as page, but nobody cares to sync page_tail
active/inactive state with page.  So we can end up with inactive page on
active lru.  The patch will fix it as well since we copy PG_active from
head page.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:03 -07:00
Naoya Horiguchi
ef2a2cbdda mm/swap.c: clear PageActive before adding pages onto unevictable list
As a result of commit 13f7f78981 ("mm: pagevec: defer deciding which
LRU to add a page to until pagevec drain time"), pages on unevictable
lists can have both of PageActive and PageUnevictable set.  This is not
only confusing, but also corrupts page migration and
shrink_[in]active_list.

This patch fixes the problem by adding ClearPageActive before adding
pages into unevictable list.  It also cleans up VM_BUG_ONs.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
2013-07-31 14:41:03 -07:00
Oleg Nesterov
3964acd0db mm: mempolicy: fix mbind_range() && vma_adjust() interaction
vma_adjust() does vma_set_policy(vma, vma_policy(next)) and this
is doubly wrong:

1. This leaks vma->vm_policy if it is not NULL and not equal to
   next->vm_policy.

   This can happen if vma_merge() expands "area", not prev (case 8).

2. This sets the wrong policy if vma_merge() joins prev and area,
   area is the vma the caller needs to update and it still has the
   old policy.

Revert commit 1444f92c84 ("mm: merging memory blocks resets
mempolicy") which introduced these problems.

Change mbind_range() to recheck mpol_equal() after vma_merge() to fix
the problem that commit tried to address.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Steven T Hampson <steven.t.hampson@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:02 -07:00
Linus Torvalds
7a62711aac Driver core patches for 3.11-rc2
Here are some driver core patches for 3.11-rc2.  They aren't really
 bugfixes, but a bunch of new helper macros for drivers to properly
 create attribute groups, which drivers and subsystems need to fix up a
 ton of race issues with incorrectly creating sysfs files (binary and
 normal) after userspace has been told that the device is present.
 
 Also here is the ability to create binary files as attribute groups, to
 solve that race condition, which was impossible to do before this, so
 that's my fault the drivers were broken.
 
 The majority of the .c changes is indenting and moving code around a
 bit.  It affects no existing code, but allows the large backlog of 70+
 patches that I already have created to start flowing into the different
 subtrees, instead of having to live in my driver-core tree, causing
 merge nightmares in linux-next for the next few months.
 
 These were finalized too late for the -rc1 merge window, which is why
 they were didn't make that pull request, testing and review from others
 didn't happen until a few weeks ago, and then there's the whole
 distraction of the past few days, which prevented these from getting to
 you sooner, sorry about that.
 
 Oh, and there's a bugfix for the documentation build warning in here as
 well.  All of these have been in linux-next this week, with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.20 (GNU/Linux)
 
 iEYEABECAAYFAlHoRUUACgkQMUfUDdst+ymkNACdHAjEXZZmXohDuCb2SqyMeQsz
 AZcAn3qqJa/NoPEgTCgOkDlAQZM6BnC5
 =+Gqk
 -----END PGP SIGNATURE-----

Merge tag 'driver-core-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core patches from Greg KH:
 "Here are some driver core patches for 3.11-rc2.  They aren't really
  bugfixes, but a bunch of new helper macros for drivers to properly
  create attribute groups, which drivers and subsystems need to fix up a
  ton of race issues with incorrectly creating sysfs files (binary and
  normal) after userspace has been told that the device is present.

  Also here is the ability to create binary files as attribute groups,
  to solve that race condition, which was impossible to do before this,
  so that's my fault the drivers were broken.

  The majority of the .c changes is indenting and moving code around a
  bit.  It affects no existing code, but allows the large backlog of 70+
  patches that I already have created to start flowing into the
  different subtrees, instead of having to live in my driver-core tree,
  causing merge nightmares in linux-next for the next few months.

  These were finalized too late for the -rc1 merge window, which is why
  they were didn't make that pull request, testing and review from
  others didn't happen until a few weeks ago, and then there's the whole
  distraction of the past few days, which prevented these from getting
  to you sooner, sorry about that.

  Oh, and there's a bugfix for the documentation build warning in here
  as well.  All of these have been in linux-next this week, with no
  reported problems"

* tag 'driver-core-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver-core: fix new kernel-doc warning in base/platform.c
  sysfs: use file mode defines from stat.h
  sysfs: add more helper macro's for (bin_)attribute(_groups)
  driver core: add default groups to struct class
  driver core: Introduce device_create_groups
  sysfs: prevent warning when only using binary attributes
  sysfs: add support for binary attributes in groups
  driver core: device.h: add RW and RO attribute macros
  sysfs.h: add BIN_ATTR macro
  sysfs.h: add ATTRIBUTE_GROUPS() macro
  sysfs.h: add __ATTR_RW() macro
2013-07-18 12:48:40 -07:00
Greg Kroah-Hartman
b9b3259746 sysfs.h: add __ATTR_RW() macro
A number of parts of the kernel created their own version of this, might
as well have the sysfs core provide it instead.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16 10:57:36 -07:00
Paul Gortmaker
0db0628d90 kernel: delete __cpuinit usage from all core kernel files
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the uses of the __cpuinit macros from C files in
the core kernel directories (kernel, init, lib, mm, and include)
that don't really have a specific maintainer.

[1] https://lkml.org/lkml/2013/5/20/589

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-07-14 19:36:59 -04:00
Linus Torvalds
54be820019 Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
Pull slab update from Pekka Enberg:
 "Highlights:

  - Fix for boot-time problems on some architectures due to
    init_lock_keys() not respecting kmalloc_caches boundaries
    (Christoph Lameter)

  - CONFIG_SLUB_CPU_PARTIAL requested by RT folks (Joonsoo Kim)

  - Fix for excessive slab freelist draining (Wanpeng Li)

  - SLUB and SLOB cleanups and fixes (various people)"

I ended up editing the branch, and this avoids two commits at the end
that were immediately reverted, and I instead just applied the oneliner
fix in between myself.

* 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
  slub: Check for page NULL before doing the node_match check
  mm/slab: Give s_next and s_stop slab-specific names
  slob: Check for NULL pointer before calling ctor()
  slub: Make cpu partial slab support configurable
  slab: add kmalloc() to kernel API documentation
  slab: fix init_lock_keys
  slob: use DIV_ROUND_UP where possible
  slub: do not put a slab to cpu partial list when cpu_partial is 0
  mm/slub: Use node_nr_slabs and node_nr_objs in get_slabinfo
  mm/slub: Drop unnecessary nr_partials
  mm/slab: Fix /proc/slabinfo unwriteable for slab
  mm/slab: Sharing s_next and s_stop between slab and slub
  mm/slab: Fix drain freelist excessively
  slob: Rework #ifdeffery in slab.h
  mm, slab: moved kmem_cache_alloc_node comment to correct place
2013-07-14 15:14:29 -07:00
Steven Rostedt
c25f195e82 slub: Check for page NULL before doing the node_match check
In the -rt kernel (mrg), we hit the following dump:

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff811573f1>] kmem_cache_alloc_node+0x51/0x180
PGD a2d39067 PUD b1641067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: sunrpc cpufreq_ondemand ipv6 tg3 joydev sg serio_raw pcspkr k8temp amd64_edac_mod edac_core i2c_piix4 e100 mii shpchp ext4 mbcache jbd2 sd_mod crc_t10dif sr_mod cdrom sata_svw ata_generic pata_acpi pata_serverworks radeon ttm drm_kms_helper drm hwmon i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod
CPU 3
Pid: 20878, comm: hackbench Not tainted 3.6.11-rt25.14.el6rt.x86_64 #1 empty empty/Tyan Transport GT24-B3992
RIP: 0010:[<ffffffff811573f1>]  [<ffffffff811573f1>] kmem_cache_alloc_node+0x51/0x180
RSP: 0018:ffff8800a9b17d70  EFLAGS: 00010213
RAX: 0000000000000000 RBX: 0000000001200011 RCX: ffff8800a06d8000
RDX: 0000000004d92a03 RSI: 00000000000000d0 RDI: ffff88013b805500
RBP: ffff8800a9b17dc0 R08: ffff88023fd14d10 R09: ffffffff81041cbd
R10: 00007f4e3f06e9d0 R11: 0000000000000246 R12: ffff88013b805500
R13: ffff8801ff46af40 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f4e3f06e700(0000) GS:ffff88023fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000000 CR3: 00000000a2d3a000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process hackbench (pid: 20878, threadinfo ffff8800a9b16000, task ffff8800a06d8000)
Stack:
 ffff8800a9b17da0 ffffffff81202e08 ffff8800a9b17de0 000000d001200011
 0000000001200011 0000000001200011 0000000000000000 0000000000000000
 00007f4e3f06e9d0 0000000000000000 ffff8800a9b17e60 ffffffff81041cbd
Call Trace:
 [<ffffffff81202e08>] ? current_has_perm+0x68/0x80
 [<ffffffff81041cbd>] copy_process+0xdd/0x15b0
 [<ffffffff810a2125>] ? rt_up_read+0x25/0x30
 [<ffffffff8104369a>] do_fork+0x5a/0x360
 [<ffffffff8107c66b>] ? migrate_enable+0xeb/0x220
 [<ffffffff8100b068>] sys_clone+0x28/0x30
 [<ffffffff81527423>] stub_clone+0x13/0x20
 [<ffffffff81527152>] ? system_call_fastpath+0x16/0x1b
Code: 89 fc 89 75 cc 41 89 d6 4d 8b 04 24 65 4c 03 04 25 48 ae 00 00 49 8b 50 08 4d 8b 28 49 8b 40 10 4d 85 ed 74 12 41 83 fe ff 74 27 <48> 8b 00 48 c1 e8 3a 41 39 c6 74 1b 8b 75 cc 4c 89 c9 44 89 f2
RIP  [<ffffffff811573f1>] kmem_cache_alloc_node+0x51/0x180
 RSP <ffff8800a9b17d70>
CR2: 0000000000000000
---[ end trace 0000000000000002 ]---

Now, this uses SLUB pretty much unmodified, but as it is the -rt kernel
with CONFIG_PREEMPT_RT set, spinlocks are mutexes, although they do
disable migration. But the SLUB code is relatively lockless, and the
spin_locks there are raw_spin_locks (not converted to mutexes), thus I
believe this bug can happen in mainline without -rt features. The -rt
patch is just good at triggering mainline bugs ;-)

Anyway, looking at where this crashed, it seems that the page variable
can be NULL when passed to the node_match() function (which does not
check if it is NULL). When this happens we get the above panic.

As page is only used in slab_alloc() to check if the node matches, if
it's NULL I'm assuming that we can say it doesn't and call the
__slab_alloc() code. Is this a correct assumption?

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-14 15:13:16 -07:00
Michel Lespinasse
98d1e64f95 mm: remove free_area_cache
Since all architectures have been converted to use vm_unmapped_area(),
there is no remaining use for the free_area_cache.

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-10 18:11:34 -07:00
Seth Jennings
2b2811178e zswap: add to mm/
zswap is a thin backend for frontswap that takes pages that are in the
process of being swapped out and attempts to compress them and store
them in a RAM-based memory pool.  This can result in a significant I/O
reduction on the swap device and, in the case where decompressing from
RAM is faster than reading from the swap device, can also improve
workload performance.

It also has support for evicting swap pages that are currently
compressed in zswap to the swap device on an LRU(ish) basis.  This
functionality makes zswap a true cache in that, once the cache is full,
the oldest pages can be moved out of zswap to the swap device so newer
pages can be compressed and stored in zswap.

This patch adds the zswap driver to mm/

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Jenifer Hopper <jhopper@us.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Hugh Dickens <hughd@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-10 18:11:34 -07:00
Seth Jennings
4e2e2770b1 zbud: add to mm/
zbud is an special purpose allocator for storing compressed pages.  It
is designed to store up to two compressed pages per physical page.
While this design limits storage density, it has simple and
deterministic reclaim properties that make it preferable to a higher
density approach when reclaim will be used.

zbud works by storing compressed pages, or "zpages", together in pairs
in a single memory page called a "zbud page".  The first buddy is "left
justifed" at the beginning of the zbud page, and the last buddy is
"right justified" at the end of the zbud page.  The benefit is that if
either buddy is freed, the freed buddy space, coalesced with whatever
slack space that existed between the buddies, results in the largest
possible free region within the zbud page.

zbud also provides an attractive lower bound on density.  The ratio of
zpages to zbud pages can not be less than 1.  This ensures that zbud can
never "do harm" by using more pages to store zpages than the
uncompressed zpages would have used on their own.

This implementation is a rewrite of the zbud allocator internally used
by zcache in the driver/staging tree.  The rewrite was necessary to
remove some of the zcache specific elements that were ingrained
throughout and provide a generic allocation interface that can later be
used by zsmalloc and others.

This patch adds zbud to mm/ for later use by zswap.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Jenifer Hopper <jhopper@us.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Hugh Dickens <hughd@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-10 18:11:34 -07:00
Andrew Morton
c103a4dc4a ipc/shmc.c: eliminate ugly 80-col tricks
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:26 -07:00
Toshi Kani
0a1be15097 mm/memory_hotplug.c: fix return value of online_pages()
online_pages() is called from memory_block_action() when a user requests
to online a memory block via sysfs.  This function needs to return a
proper error value in case of error.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:25 -07:00
Michal Hocko
5f12733e9d mm: honor min_free_kbytes set by user
min_free_kbytes is updated during memory hotplug (by
init_per_zone_wmark_min) currently which is right thing to do in most
cases but this could be unexpected if admin increased the value to
prevent from allocation failures and the new min_free_kbytes would be
decreased as a result of memory hotadd.

This patch saves the user defined value and allows updating
min_free_kbytes only if it is higher than the saved one.

A warning is printed when the new value is ignored.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:25 -07:00
Li Zefan
465939a1fa memcg: don't need to free memcg via RCU or workqueue
Now memcg has the same life cycle with its corresponding cgroup, and a
cgroup is freed via RCU and then mem_cgroup_css_free() will be called in
a work function, so we can simply call __mem_cgroup_free() in
mem_cgroup_css_free().

This actually reverts commit 59927fb984 ("memcg: free mem_cgroup by RCU
to fix oops").

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Li Zefan
e0743e6bc5 memcg: kill memcg refcnt
Now memcg has the same life cycle as its corresponding cgroup.  Kill the
useless refcnt.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Li Zefan
8d76a97978 memcg: don't need to get a reference to the parent
The cgroup core guarantees it's always safe to access the parent.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Li Zefan
4050377b50 memcg: use css_get/put for swap memcg
Use css_get/put instead of mem_cgroup_get/put.  A simple replacement
will do.

The historical reason that memcg has its own refcnt instead of always
using css_get/put, is that cgroup couldn't be removed if there're still
css refs, so css refs can't be used as long-lived reference.  The
situation has changed so that rmdir a cgroup will succeed regardless css
refs, but won't be freed until css refs goes down to 0.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Li Zefan
10d5ebf40f memcg: use css_get/put when charging/uncharging kmem
Use css_get/put instead of mem_cgroup_get/put.

We can't do a simple replacement, because here mem_cgroup_put() is
called during mem_cgroup_css_free(), while mem_cgroup_css_free() won't
be called until css refcnt goes down to 0.

Instead we increment css refcnt in mem_cgroup_css_offline(), and then
check if there's still kmem charges.  If not, css refcnt will be
decremented immediately, otherwise the refcnt will be released after the
last kmem allocation is uncahred.

[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Li Zefan
20f05310ba memcg: don't use mem_cgroup_get() when creating a kmemcg cache
Use css_get()/css_put() instead of mem_cgroup_get()/mem_cgroup_put().

There are two things being done in the current code:

First, we acquired a css_ref to make sure that the underlying cgroup
would not go away.  That is a short lived reference, and it is put as
soon as the cache is created.

At this point, we acquire a long-lived per-cache memcg reference count
to guarantee that the memcg will still be alive.

so it is:

  enqueue: css_get
  create : memcg_get, css_put
  destroy: memcg_put

So we only need to get rid of the memcg_get, change the memcg_put to
css_put, and get rid of the now extra css_put.

(This changelog is mostly written by Glauber)

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Li Zefan
5347e5ae13 memcg: use css_get() in sock_update_memcg()
Use css_get/css_put instead of mem_cgroup_get/put.

Note, if at the same time someone is moving @current to a different
cgroup and removing the old cgroup, css_tryget() may return false, and
sock->sk_cgrp won't be initialized, which is fine.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Michal Hocko
f37a96914d memcg, kmem: fix reference count handling on the error path
mem_cgroup_css_online calls mem_cgroup_put if memcg_init_kmem fails.
This is not correct because only memcg_propagate_kmem takes an
additional reference while mem_cgroup_sockets_init is allowed to fail as
well (although no current implementation fails) but it doesn't take any
reference.  This all suggests that it should be memcg_propagate_kmem
that should clean up after itself so this patch moves mem_cgroup_put
over there.

Unfortunately this is not that easy (as pointed out by Li Zefan) because
memcg_kmem_mark_dead marks the group dead (KMEM_ACCOUNTED_DEAD) if it is
marked active (KMEM_ACCOUNTED_ACTIVE) which is the case even if
memcg_propagate_kmem fails so the additional reference is dropped in
that case in kmem_cgroup_destroy which means that the reference would be
dropped two times.

The easiest way then would be to simply remove mem_cgrroup_put from
mem_cgroup_css_online and rely on kmem_cgroup_destroy doing the right
thing.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>	[3.8]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Michal Hocko
fa460c2d37 Revert "memcg: avoid dangling reference count in creation failure"
This reverts commit e4715f01be.

mem_cgroup_put is hierarchy aware so mem_cgroup_put(memcg) already drops
an additional reference from all parents so the additional
mem_cgrroup_put(parent) potentially causes use-after-free.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>	[3.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Jörn Engel
493af57804 mmap: allow MAP_HUGETLB for hugetlbfs files v2
It is counterintuitive at best that mmap'ing a hugetlbfs file with
MAP_HUGETLB fails, while mmap'ing it without will a) succeed and b)
return huge pages.

v2: use is_file_hugepages(), as suggested by Jianguo

Signed-off-by: Joern Engel <joern@logfs.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:24 -07:00
Mel Gorman
918fc718c5 mm: vmscan: do not scale writeback pages when deciding whether to set ZONE_WRITEBACK
After the patch "mm: vmscan: Flatten kswapd priority loop" was merged
the scanning priority of kswapd changed.

The priority now rises until it is scanning enough pages to meet the
high watermark.  shrink_inactive_list sets ZONE_WRITEBACK if a number of
pages were encountered under writeback but this value is scaled based on
the priority.  As kswapd frequently scans with a higher priority now it
is relatively easy to set ZONE_WRITEBACK.  This patch removes the
scaling and treates writeback pages similar to how it treats unqueued
dirty pages and congested pages.  The user-visible effect should be that
kswapd will writeback fewer pages from reclaim context.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:23 -07:00