Commit Graph

8431 Commits

Author SHA1 Message Date
Dan Streetman 12d79d64bf mm/zpool: update zswap to use zpool
Change zswap to use the zpool api instead of directly using zbud.  Add a
boot-time param to allow selecting which zpool implementation to use,
with zbud as the default.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Tested-by: Seth Jennings <sjennings@variantweb.net>
Cc: Weijie Yang <weijie.yang@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:23 -07:00
Dan Streetman c795779df2 mm/zpool: zbud/zsmalloc implement zpool
Update zbud and zsmalloc to implement the zpool api.

[fengguang.wu@intel.com: make functions static]
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Tested-by: Seth Jennings <sjennings@variantweb.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Weijie Yang <weijie.yang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:23 -07:00
Dan Streetman af8d417a04 mm/zpool: implement common zpool api to zbud/zsmalloc
Add zpool api.

zpool provides an interface for memory storage, typically of compressed
memory.  Users can select what backend to use; currently the only
implementations are zbud, a low density implementation with up to two
compressed pages per storage page, and zsmalloc, a higher density
implementation with multiple compressed pages per storage page.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Tested-by: Seth Jennings <sjennings@variantweb.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Weijie Yang <weijie.yang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:23 -07:00
Dan Streetman 99eef8e936 mm/zbud: change zbud_alloc size type to size_t
Change the type of the zbud_alloc() size param from unsigned int to
size_t.

Technically, this should not make any difference, as the zbud
implementation already restricts the size to well within either type's
limits; but as zsmalloc (and kmalloc) use size_t, and zpool will use
size_t, this brings the size parameter type in line with zsmalloc/zpool.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Acked-by: Seth Jennings <sjennings@variantweb.net>
Tested-by: Seth Jennings <sjennings@variantweb.net>
Cc: Weijie Yang <weijie.yang@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:23 -07:00
Max Filippov 15de36a4c3 mm/highmem: make kmap cache coloring aware
User-visible effect:
 Architectures that choose this method of maintaining cache coherency
(MIPS and xtensa currently) are able to use high memory on cores with
aliasing data cache.  Without this fix such architectures can not use
high memory (in case of xtensa it means that at most 128 MBytes of
physical memory is available).

The problem:
 VIPT cache with way size larger than MMU page size may suffer from
aliasing problem: a single physical address accessed via different
virtual addresses may end up in multiple locations in the cache.
Virtual mappings of a physical address that always get cached in
different cache locations are said to have different colors.  L1 caching
hardware usually doesn't handle this situation leaving it up to
software.  Software must avoid this situation as it leads to data
corruption.

What can be done:
 One way to handle this is to flush and invalidate data cache every time
page mapping changes color.  The other way is to always map physical
page at a virtual address with the same color.  Low memory pages already
have this property.  Giving architecture a way to control color of high
memory page mapping allows reusing of existing low memory cache alias
handling code.

How this is done with this patch:
 Provide hooks that allow architectures with aliasing cache to align
mapping address of high pages according to their color.  Such
architectures may enforce similar coloring of low- and high-memory page
mappings and reuse existing cache management functions to support
highmem.

This code is based on the implementation of similar feature for MIPS by
Leonid Yegoshin.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Marc Gauthier <marc@cadence.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Steven Hill <Steven.Hill@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
Peter Zijlstra b972216e27 mmu_notifier: add call_srcu and sync function for listener to delay call and sync
When kernel device drivers or subsystems want to bind their lifespan to
t= he lifespan of the mm_struct, they usually use one of the following
methods:

1. Manually calling a function in the interested kernel module.  The
   funct= ion call needs to be placed in mmput.  This method was rejected
   by several ker= nel maintainers.

2. Registering to the mmu notifier release mechanism.

The problem with the latter approach is that the mmu_notifier_release
cal= lback is called from__mmu_notifier_release (called from exit_mmap).
That functi= on iterates over the list of mmu notifiers and don't expect
the release call= back function to remove itself from the list.
Therefore, the callback function= in the kernel module can't release the
mmu_notifier_object, which is actuall= y the kernel module's object
itself.  As a result, the destruction of the kernel module's object must
to be done in a delayed fashion.

This patch adds support for this delayed callback, by adding a new
mmu_notifier_call_srcu function that receives a function ptr and calls
th= at function with call_srcu.  In that function, the kernel module
releases its object.  To use mmu_notifier_call_srcu, the calling module
needs to call b= efore that a new function called
mmu_notifier_unregister_no_release that as its= name implies,
unregisters a notifier without calling its notifier release call= back.

This patch also adds a function that will call barrier_srcu so those
kern= el modules can sync with mmu_notifier.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
Johannes Weiner 61e02c7457 mm: memcontrol: clean up reclaim size variable use in try_charge()
Charge reclaim and OOM currently use the charge batch variable, but
batching is already disabled at that point.  To simplify the charge
logic, the batch variable is reset to the original request size when
reclaim is entered, so it's functionally equal, but it's misleading.

Switch reclaim/OOM to nr_pages, which is the original request size.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
Rik van Riel dbffcd03d7 mm: change confusing #ifdef use in __access_remote_vm
This patch changes confusing #ifdef use in __access_remote_vm into
merely ugly #ifdef use.

Addresses bug https://bugzilla.kernel.org/show_bug.cgi?id=81651

Signed-off-by: Rik van Riel <riel@redhat.com>
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
Kirill A. Shutemov 3a91053aeb mm: mark fault_around_bytes __read_mostly
fault_around_bytes can only be changed via debugfs.  Let's mark it
read-mostly.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Suggested-by: David Rientjes <rientjes@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
Kirill A. Shutemov aecd6f4426 mm: close race between do_fault_around() and fault_around_bytes_set()
Things can go wrong if fault_around_bytes will be changed under
do_fault_around(): between fault_around_mask() and fault_around_pages().

Let's read fault_around_bytes only once during do_fault_around() and
calculate mask based on the reading.

Note: fault_around_bytes can only be updated via debug interface.  Also
I've tried but was not able to trigger a bad behaviour without the
patch.  So I would not consider this patch as urgent.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Sasha Levin <sasha.levin@oracle.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>
2014-08-06 18:01:22 -07:00
Jerome Marchand 2ab051e11b memcg, vmscan: Fix forced scan of anonymous pages
When memory cgoups are enabled, the code that decides to force to scan
anonymous pages in get_scan_count() compares global values (free,
high_watermark) to a value that is restricted to a memory cgroup (file).
It make the code over-eager to force anon scan.

For instance, it will force anon scan when scanning a memcg that is
mainly populated by anonymous page, even when there is plenty of file
pages to get rid of in others memcgs, even when swappiness == 0.  It
breaks user's expectation about swappiness and hurts performance.

This patch makes sure that forced anon scan only happens when there not
enough file pages for the all zone, not just in one random memcg.

[hannes@cmpxchg.org: cleanups]
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
Jerome Marchand 7c0db9e917 mm, vmscan: fix an outdated comment still mentioning get_scan_ratio
Quite a while ago, get_scan_ratio() has been renamed get_scan_count(),
however a comment in shrink_active_list() still mention it.  This patch
fixes the outdated comment.

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
David Rientjes fb794bcbb4 mm, oom: remove unnecessary exit_state check
The oom killer scans each process and determines whether it is eligible
for oom kill or whether the oom killer should abort because of
concurrent memory freeing.  It will abort when an eligible process is
found to have TIF_MEMDIE set, meaning it has already been oom killed and
we're waiting for it to exit.

Processes with task->mm == NULL should not be considered because they
are either kthreads or have already detached their memory and killing
them would not lead to memory freeing.  That memory is only freed after
exit_mm() has returned, however, and not when task->mm is first set to
NULL.

Clear TIF_MEMDIE after exit_mm()'s mmput() so that an oom killed process
is no longer considered for oom kill, but only until exit_mm() has
returned.  This was fragile in the past because it relied on
exit_notify() to be reached before no longer considering TIF_MEMDIE
processes.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:21 -07:00
Li Zhong d017763931 mm: fix potential infinite loop in dissolve_free_huge_pages()
It is possible for some platforms, such as powerpc to set HPAGE_SHIFT to
0 to indicate huge pages not supported.

When this is the case, hugetlbfs could be disabled during boot time:
hugetlbfs: disabling because there are no supported hugepage sizes

Then in dissolve_free_huge_pages(), order is kept maximum (64 for
64bits), and the for loop below won't end: for (pfn = start_pfn; pfn <
end_pfn; pfn += 1 << order)

As suggested by Naoya, below fix checks hugepages_supported() before
calling dissolve_free_huge_pages().

[rientjes@google.com: no legitimate reason to call dissolve_free_huge_pages() when !hugepages_supported()]
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>	[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:21 -07:00
David Rientjes 8fe780484d mm, thp: restructure thp avoidance of light synchronous migration
__GFP_NO_KSWAPD, once the way to determine if an allocation was for thp
or not, has gained more users.  Their use is not necessarily wrong, they
are trying to do a memory allocation that can easily fail without
disturbing kswapd, so the bit has gained additional usecases.

This restructures the check to determine whether MIGRATE_SYNC_LIGHT
should be used for memory compaction in the page allocator.  Rather than
testing solely for __GFP_NO_KSWAPD, test for all bits that must be set
for thp allocations.

This also moves the check to be done only after the page allocator is
aborted for deferred or contended memory compaction since setting
migration_mode for this case is pointless.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.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>
2014-08-06 18:01:21 -07:00
David Rientjes e972a070e2 mm, oom: rename zonelist locking functions
try_set_zonelist_oom() and clear_zonelist_oom() are not named properly
to imply that they require locking semantics to avoid out_of_memory()
being reordered.

zone_scan_lock is required for both functions to ensure that there is
proper locking synchronization.

Rename try_set_zonelist_oom() to oom_zonelist_trylock() and rename
clear_zonelist_oom() to oom_zonelist_unlock() to imply there is proper
locking semantics.

At the same time, convert oom_zonelist_trylock() to return bool instead
of int since only success and failure are tested.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:21 -07:00
David Rientjes 8d060bf490 mm, oom: ensure memoryless node zonelist always includes zones
With memoryless node support being worked on, it's possible that for
optimizations that a node may not have a non-NULL zonelist.  When
CONFIG_NUMA is enabled and node 0 is memoryless, this means the zonelist
for first_online_node may become NULL.

The oom killer requires a zonelist that includes all memory zones for
the sysrq trigger and pagefault out of memory handler.

Ensure that a non-NULL zonelist is always passed to the oom killer.

[akpm@linux-foundation.org: fix non-numa build]
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:21 -07:00
Wang Nan 6326440077 memory-hotplug: add zone_for_memory() for selecting zone for new memory
This series of patches fixes a problem when adding memory in bad manner.
For example: for a x86_64 machine booted with "mem=400M" and with 2GiB
memory installed, following commands cause problem:

  # echo 0x40000000 > /sys/devices/system/memory/probe
 [   28.613895] init_memory_mapping: [mem 0x40000000-0x47ffffff]
  # echo 0x48000000 > /sys/devices/system/memory/probe
 [   28.693675] init_memory_mapping: [mem 0x48000000-0x4fffffff]
  # echo online_movable > /sys/devices/system/memory/memory9/state
  # echo 0x50000000 > /sys/devices/system/memory/probe
 [   29.084090] init_memory_mapping: [mem 0x50000000-0x57ffffff]
  # echo 0x58000000 > /sys/devices/system/memory/probe
 [   29.151880] init_memory_mapping: [mem 0x58000000-0x5fffffff]
  # echo online_movable > /sys/devices/system/memory/memory11/state
  # echo online> /sys/devices/system/memory/memory8/state
  # echo online> /sys/devices/system/memory/memory10/state
  # echo offline> /sys/devices/system/memory/memory9/state
 [   30.558819] Offlined Pages 32768
  # free
              total       used       free     shared    buffers     cached
 Mem:        780588 18014398509432020     830552          0          0      51180
 -/+ buffers/cache: 18014398509380840     881732
 Swap:            0          0          0

This is because the above commands probe higher memory after online a
section with online_movable, which causes ZONE_HIGHMEM (or ZONE_NORMAL
for systems without ZONE_HIGHMEM) overlaps ZONE_MOVABLE.

After the second online_movable, the problem can be observed from
zoneinfo:

  # cat /proc/zoneinfo
  ...
  Node 0, zone  Movable
    pages free     65491
          min      250
          low      312
          high     375
          scanned  0
          spanned  18446744073709518848
          present  65536
          managed  65536
  ...

This series of patches solve the problem by checking ZONE_MOVABLE when
choosing zone for new memory.  If new memory is inside or higher than
ZONE_MOVABLE, makes it go there instead.

After applying this series of patches, following are free and zoneinfo
result (after offlining memory9):

  bash-4.2# free
                total       used       free     shared    buffers     cached
   Mem:        780956      80112     700844          0          0      51180
   -/+ buffers/cache:      28932     752024
   Swap:            0          0          0

  bash-4.2# cat /proc/zoneinfo

  Node 0, zone      DMA
    pages free     3389
          min      14
          low      17
          high     21
          scanned  0
          spanned  4095
          present  3998
          managed  3977
      nr_free_pages 3389
  ...
    start_pfn:         1
    inactive_ratio:    1
  Node 0, zone    DMA32
    pages free     73724
          min      341
          low      426
          high     511
          scanned  0
          spanned  98304
          present  98304
          managed  92958
      nr_free_pages 73724
    ...
    start_pfn:         4096
    inactive_ratio:    1
  Node 0, zone   Normal
    pages free     32630
          min      120
          low      150
          high     180
          scanned  0
          spanned  32768
          present  32768
          managed  32768
      nr_free_pages 32630
  ...
    start_pfn:         262144
    inactive_ratio:    1
  Node 0, zone  Movable
    pages free     65476
          min      241
          low      301
          high     361
          scanned  0
          spanned  98304
          present  65536
          managed  65536
      nr_free_pages 65476
  ...
    start_pfn:         294912
    inactive_ratio:    1

This patch (of 7):

Introduce zone_for_memory() in arch independent code for
arch_add_memory() use.

Many arch_add_memory() function simply selects ZONE_HIGHMEM or
ZONE_NORMAL and add new memory into it.  However, with the existance of
ZONE_MOVABLE, the selection method should be carefully considered: if
new, higher memory is added after ZONE_MOVABLE is setup, the default
zone and ZONE_MOVABLE may overlap each other.

should_add_memory_movable() checks the status of ZONE_MOVABLE.  If it
has already contain memory, compare the address of new memory and
movable memory.  If new memory is higher than movable, it should be
added into ZONE_MOVABLE instead of default zone.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Mel Gorman" <mgorman@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:21 -07:00
Vladimir Davydov aee52cae00 slub: remove kmemcg id from create_unique_id
This function is never called for memcg caches, because they are
unmergeable, so remove the dead code.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Reviewed-by: 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>
2014-08-06 18:01:21 -07:00
David Rientjes 9ef0a0ffa2 mm, writeback: prevent race when calculating dirty limits
Setting vm_dirty_bytes and dirty_background_bytes is not protected by
any serialization.

Therefore, it's possible for either variable to change value after the
test in global_dirty_limits() to determine whether available_memory
needs to be initialized or not.

Always ensure that available_memory is properly initialized.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:21 -07:00
David Rientjes 14a4e2141e mm, thp: only collapse hugepages to nodes with affinity for zone_reclaim_mode
Commit 9f1b868a13 ("mm: thp: khugepaged: add policy for finding target
node") improved the previous khugepaged logic which allocated a
transparent hugepages from the node of the first page being collapsed.

However, it is still possible to collapse pages to remote memory which
may suffer from additional access latency.  With the current policy, it
is possible that 255 pages (with PAGE_SHIFT == 12) will be collapsed
remotely if the majority are allocated from that node.

When zone_reclaim_mode is enabled, it means the VM should make every
attempt to allocate locally to prevent NUMA performance degradation.  In
this case, we do not want to collapse hugepages to remote nodes that
would suffer from increased access latency.  Thus, when
zone_reclaim_mode is enabled, only allow collapsing to nodes with
RECLAIM_DISTANCE or less.

There is no functional change for systems that disable
zone_reclaim_mode.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
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>
2014-08-06 18:01:20 -07:00
Wang Sheng-Hui fed400a181 mm/shmem.c: remove the unused gfp arg to shmem_add_to_page_cache()
The gfp arg is not used in shmem_add_to_page_cache.  Remove this unused
arg.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
Paul Cassella 9a95f3cf7b mm: describe mmap_sem rules for __lock_page_or_retry() and callers
Add a comment describing the circumstances in which
__lock_page_or_retry() will or will not release the mmap_sem when
returning 0.

Add comments to lock_page_or_retry()'s callers (filemap_fault(),
do_swap_page()) noting the impact on VM_FAULT_RETRY returns.

Add comments on up the call tree, particularly replacing the false "We
return with mmap_sem still held" comments.

Signed-off-by: Paul Cassella <cassella@cray.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
Mel Gorman 4ffeaf3560 mm: page_alloc: reduce cost of the fair zone allocation policy
The fair zone allocation policy round-robins allocations between zones
within a node to avoid age inversion problems during reclaim.  If the
first allocation fails, the batch counts are reset and a second attempt
made before entering the slow path.

One assumption made with this scheme is that batches expire at roughly
the same time and the resets each time are justified.  This assumption
does not hold when zones reach their low watermark as the batches will
be consumed at uneven rates.  Allocation failure due to watermark
depletion result in additional zonelist scans for the reset and another
watermark check before hitting the slowpath.

On UMA, the benefit is negligible -- around 0.25%.  On 4-socket NUMA
machine it's variable due to the variability of measuring overhead with
the vmstat changes.  The system CPU overhead comparison looks like

          3.16.0-rc3  3.16.0-rc3  3.16.0-rc3
             vanilla   vmstat-v5 lowercost-v5
User          746.94      774.56      802.00
System      65336.22    32847.27    40852.33
Elapsed     27553.52    27415.04    27368.46

However it is worth noting that the overall benchmark still completed
faster and intuitively it makes sense to take as few passes as possible
through the zonelists.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
Mel Gorman f7b5d64794 mm: page_alloc: abort fair zone allocation policy when remotes nodes are encountered
The purpose of numa_zonelist_order=zone is to preserve lower zones for
use with 32-bit devices.  If locality is preferred then the
numa_zonelist_order=node policy should be used.

Unfortunately, the fair zone allocation policy overrides this by
skipping zones on remote nodes until the lower one is found.  While this
makes sense from a page aging and performance perspective, it breaks the
expected zonelist policy.  This patch restores the expected behaviour
for zone-list ordering.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
Mel Gorman bb0b6dffa2 mm: vmscan: only update per-cpu thresholds for online CPU
When kswapd is awake reclaiming, the per-cpu stat thresholds are lowered
to get more accurate counts to avoid breaching watermarks.  This
threshold update iterates over all possible CPUs which is unnecessary.
Only online CPUs need to be updated.  If a new CPU is onlined,
refresh_zone_stat_thresholds() will set the thresholds correctly.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
Mel Gorman 0d5d823ab4 mm: move zone->pages_scanned into a vmstat counter
zone->pages_scanned is a write-intensive cache line during page reclaim
and it's also updated during page free.  Move the counter into vmstat to
take advantage of the per-cpu updates and do not update it in the free
paths unless necessary.

On a small UMA machine running tiobench the difference is marginal.  On
a 4-node machine the overhead is more noticable.  Note that automatic
NUMA balancing was disabled for this test as otherwise the system CPU
overhead is unpredictable.

          3.16.0-rc3  3.16.0-rc3  3.16.0-rc3
             vanillarearrange-v5   vmstat-v5
User          746.94      759.78      774.56
System      65336.22    58350.98    32847.27
Elapsed     27553.52    27282.02    27415.04

Note that the overhead reduction will vary depending on where exactly
pages are allocated and freed.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
Mel Gorman 3484b2de94 mm: rearrange zone fields into read-only, page alloc, statistics and page reclaim lines
The arrangement of struct zone has changed over time and now it has
reached the point where there is some inappropriate sharing going on.
On x86-64 for example

o The zone->node field is shared with the zone lock and zone->node is
  accessed frequently from the page allocator due to the fair zone
  allocation policy.

o span_seqlock is almost never used by shares a line with free_area

o Some zone statistics share a cache line with the LRU lock so
  reclaim-intensive and allocator-intensive workloads can bounce the cache
  line on a stat update

This patch rearranges struct zone to put read-only and read-mostly
fields together and then splits the page allocator intensive fields, the
zone statistics and the page reclaim intensive fields into their own
cache lines.  Note that the type of lowmem_reserve changes due to the
watermark calculations being signed and avoiding a signed/unsigned
conversion there.

On the test configuration I used the overall size of struct zone shrunk
by one cache line.  On smaller machines, this is not likely to be
noticable.  However, on a 4-node NUMA machine running tiobench the
system CPU overhead is reduced by this patch.

          3.16.0-rc3  3.16.0-rc3
             vanillarearrange-v5r9
User          746.94      759.78
System      65336.22    58350.98
Elapsed     27553.52    27282.02

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
Mel Gorman 24b7e5819a mm: pagemap: avoid unnecessary overhead when tracepoints are deactivated
This was formerly the series "Improve sequential read throughput" which
noted some major differences in performance of tiobench since 3.0.
While there are a number of factors, two that dominated were the
introduction of the fair zone allocation policy and changes to CFQ.

The behaviour of fair zone allocation policy makes more sense than
tiobench as a benchmark and CFQ defaults were not changed due to
insufficient benchmarking.

This series is what's left.  It's one functional fix to the fair zone
allocation policy when used on NUMA machines and a reduction of overhead
in general.  tiobench was used for the comparison despite its flaws as
an IO benchmark as in this case we are primarily interested in the
overhead of page allocator and page reclaim activity.

On UMA, it makes little difference to overhead

          3.16.0-rc3   3.16.0-rc3
             vanilla lowercost-v5
User          383.61      386.77
System        403.83      401.74
Elapsed      5411.50     5413.11

On a 4-socket NUMA machine it's a bit more noticable

          3.16.0-rc3   3.16.0-rc3
             vanilla lowercost-v5
User          746.94      802.00
System      65336.22    40852.33
Elapsed     27553.52    27368.46

This patch (of 6):

The LRU insertion and activate tracepoints take PFN as a parameter
forcing the overhead to the caller.  Move the overhead to the tracepoint
fast-assign method to ensure the cost is only incurred when the
tracepoint is active.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
Wang Sheng-Hui d0480be44a mm: update the description for vm_total_pages
vm_total_pages is calculated by nr_free_pagecache_pages(), which counts
the number of pages which are beyond the high watermark within all
zones.  So vm_total_pages is not equal to total number of pages which
the VM controls.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.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>
2014-08-06 18:01:20 -07:00
Cyrill Gorcunov 9aed8614af mm/memory.c: don't forget to set softdirty on file mapped fault
Otherwise we may not notice that pte was softdirty because
pte_mksoft_dirty helper _returns_ new pte but doesn't modify the
argument.

In case if page fault happend on dirty filemapping the newly created pte
may loose softdirty bit thus if a userspace program is tracking memory
changes with help of a memory tracker (CONFIG_MEM_SOFT_DIRTY) it might
miss modification of a memory page (which in worts case may lead to data
inconsistency).

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
WANG Chao f6f8ed4735 mm/vmalloc.c: clean up map_vm_area third argument
Currently map_vm_area() takes (struct page *** pages) as third argument,
and after mapping, it moves (*pages) to point to (*pages +
nr_mappped_pages).

It looks like this kind of increment is useless to its caller these
days.  The callers don't care about the increments and actually they're
trying to avoid this by passing another copy to map_vm_area().

The caller can always guarantee all the pages can be mapped into vm_area
as specified in first argument and the caller only cares about whether
map_vm_area() fails or not.

This patch cleans up the pointer movement in map_vm_area() and updates
its callers accordingly.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:19 -07:00
Jerome Marchand 21bda264f4 mm: make copy_pte_range static again
Commit 71e3aac072 ("thp: transparent hugepage core") adds
copy_pte_range prototype to huge_mm.h.  I'm not sure why (or if) this
function have been used outside of memory.c, but it currently isn't.
This patch makes copy_pte_range() static again.

Signed-off-by: Jerome Marchand <jmarchan@redhat.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>
2014-08-06 18:01:19 -07:00
David Rientjes ed4d4902eb mm, hugetlb: remove hugetlb_zero and hugetlb_infinity
They are unnecessary: "zero" can be used in place of "hugetlb_zero" and
passing extra2 == NULL is equivalent to infinity.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.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>
2014-08-06 18:01:19 -07:00
David Rientjes 238d3c13f0 mm, hugetlb: generalize writes to nr_hugepages
Three different interfaces alter the maximum number of hugepages for an
hstate:

 - /proc/sys/vm/nr_hugepages for global number of hugepages of the default
   hstate,

 - /sys/kernel/mm/hugepages/hugepages-X/nr_hugepages for global number of
   hugepages for a specific hstate, and

 - /sys/kernel/mm/hugepages/hugepages-X/nr_hugepages/mempolicy for number of
   hugepages for a specific hstate over the set of allowed nodes.

Generalize the code so that a single function handles all of these
writes instead of duplicating the code in two different functions.

This decreases the number of lines of code, but also reduces the size of
.text by about half a percent since set_max_huge_pages() can be inlined.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Acked-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:19 -07:00
Andi Kleen f37d4298aa hwpoison: fix race with changing page during offlining
When a hwpoison page is locked it could change state due to parallel
modifications.  The original compound page can be torn down and then
this 4k page becomes part of a differently-size compound page is is a
standalone regular page.

Check after the lock if the page is still the same compound page.

We could go back, grab the new head page and try again but it should be
quite rare, so I thought this was safest.  A retry loop would be more
difficult to test and may have more side effects.

The hwpoison code by design only tries to handle cases that are
reasonably common in workloads, as visible in page-flags.

I'm not really that concerned about handling this (likely rare case),
just not crashing on it.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: 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>
2014-08-06 18:01:19 -07:00
Davidlohr Bueso ad4404a226 mm,hugetlb: simplify error handling in hugetlb_cow()
When returning from hugetlb_cow(), we always (1) put back the refcount
for each referenced page -- always 'old', and 'new' if allocation was
successful.  And (2) retake the page table lock right before returning,
as the callers expects.  This logic can be simplified and encapsulated,
as proposed in this patch.  In addition to cleaner code, we also shave a
few bytes off the instruction text:

   text    data     bss     dec     hex filename
  28399     462   41328   70189   1122d mm/hugetlb.o-baseline
  28367     462   41328   70157   1120d mm/hugetlb.o-patched

Passes libhugetlbfs testcases.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.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>
2014-08-06 18:01:19 -07:00
Davidlohr Bueso 2f4612af43 mm,hugetlb: make unmap_ref_private() return void
This function always returns 1, thus no need to check return value in
hugetlb_cow().  By doing so, we can get rid of the unnecessary WARN_ON
call.  While this logic perhaps existed as a way of identifying future
unmap_ref_private() mishandling, reality is it serves no apparent
purpose.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.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>
2014-08-06 18:01:19 -07:00
Hugh Dickins eb39d618f9 mm: replace init_page_accessed by __SetPageReferenced
Do we really need an exported alias for __SetPageReferenced()? Its
callers better know what they're doing, in which case the page would not
be already marked referenced.  Kill init_page_accessed(), just
__SetPageReferenced() inline.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:19 -07:00
Fabian Frederick c2ea2181db mm/hwpoison-inject.c: remove unnecessary null test before debugfs_remove_recursive
Fix checkpatch warning:
  "WARNING: debugfs_remove_recursive(NULL) is safe this check is probably not required"

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: 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>
2014-08-06 18:01:19 -07:00
Rafael Aquini cc7452b6dc mm: export NR_SHMEM via sysinfo(2) / si_meminfo() interfaces
Historically, we exported shared pages to userspace via sysinfo(2)
sharedram and /proc/meminfo's "MemShared" fields.  With the advent of
tmpfs, from kernel v2.4 onward, that old way for accounting shared mem
was deemed inaccurate and we started to export a hard-coded 0 for
sysinfo.sharedram.  Later on, during the 2.6 timeframe, "MemShared" got
re-introduced to /proc/meminfo re-branded as "Shmem", but we're still
reporting sysinfo.sharedmem as that old hard-coded zero, which makes the
"shared memory" report inconsistent across interfaces.

This patch leverages the addition of explicit accounting for pages used
by shmem/tmpfs -- "4b02108 mm: oom analysis: add shmem vmstat" -- in
order to make the users of sysinfo(2) and si_meminfo*() friends aware of
that vmstat entry and make them report it consistently across the
interfaces, as well to make sysinfo(2) returned data consistent with our
current API documentation states.

Signed-off-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
2014-08-06 18:01:19 -07:00
Konstantin Khlebnikov 82f71ae4a2 mm: catch memory commitment underflow
Print a warning (if CONFIG_DEBUG_VM=y) when memory commitment becomes
too negative.

This shouldn't happen any more - the previous two patches fixed the
committed_as underflow issues.

[akpm@linux-foundation.org: use VM_WARN_ONCE, per Dave]
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Hugh Dickins <hughd@google.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>
2014-08-06 18:01:19 -07:00
Konstantin Khlebnikov 7714251799 shmem: update memory reservation on truncate
A shared anonymous mapping created without MAP_NORESERVE holds memory
reservation for whole range of shmem segment.  Usually there is no way
to change its size, but /proc/<pid>/map_files/...  (available if
CONFIG_CHECKPOINT_RESTORE=y) allows that.

This patch adjusts the memory reservation in shmem_setattr().

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:19 -07:00
Konstantin Khlebnikov 66ee4b8887 shmem: fix double uncharge in __shmem_file_setup()
If __shmem_file_setup() fails on struct file allocation it uncharges
memory commitment twice: first by shmem_unacct_size() and second time
implicitly in shmem_evict_inode() when it kills the newly created inode.

This patch removes shmem_unacct_size() from error path if the inode was
already there.

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:18 -07:00
David Rientjes 930f036b4f mm, vmalloc: constify allocation mask
tmp_mask in the __vmalloc_area_node() iteration never changes so it can
be moved into function scope and marked with const.  This causes the
movl and orl to only be done once per call rather than area->nr_pages
times.

nested_gfp can also be marked const.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:18 -07:00
Eric Dumazet 660654f90e mm/vmalloc.c: add a schedule point to vmalloc()
It is not uncommon on busy servers to get stuck hundred of ms in
vmalloc() calls (like file descriptor expansions).

Add a cond_resched() to __vmalloc_area_node() to be gentle to
other tasks.

[akpm@linux-foundation.org: only do it for __GFP_WAIT, per David]
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hugh Dickins <hughd@google.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>
2014-08-06 18:01:18 -07:00
Wang Sheng-Hui 54980b93c0 mm: update the description for madvise_remove
Currently, we have more filesystems supporting fallocate, e.g
ext4/btrfs.  Remove the outdated comment for madvise_remove.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Reviewed-by: 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>
2014-08-06 18:01:18 -07:00
Johannes Weiner ee814fe23d mm: vmscan: clean up struct scan_control
Reorder the members by input and output, then turn the individual
integers for may_writepage, may_unmap, may_swap, compaction_ready,
hibernation_mode into bit fields to save stack space:

  +72/-296 -224
  kswapd                                       104     176     +72
  try_to_free_pages                             80      56     -24
  try_to_free_mem_cgroup_pages                  80      56     -24
  shrink_all_memory                             88      64     -24
  reclaim_clean_pages_from_list                168     144     -24
  mem_cgroup_shrink_node_zone                  104      80     -24
  __zone_reclaim                               176     152     -24
  balance_pgdat                                152       -    -152

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Mel Gorman <mgorman@suse.de>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:18 -07:00
Johannes Weiner 02695175c7 mm: vmscan: move swappiness out of scan_control
Swappiness is determined for each scanned memcg individually in
shrink_zone() and is not a parameter that applies throughout the reclaim
scan.  Move it out of struct scan_control to prevent accidental use of a
stale value.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:18 -07:00
Johannes Weiner 2344d7e44b mm: vmscan: remove all_unreclaimable()
Direct reclaim currently calls shrink_zones() to reclaim all members of
a zonelist, and if that wasn't successful it does another pass through
the same zonelist to check overall reclaimability.

Just check reclaimability in shrink_zones() directly and propagate the
result through the return value.  Then remove all_unreclaimable().

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:18 -07:00