android_kernel_samsung_msm8976/mm
Minchan Kim f06590bd71 mm: vmscan: correctly check if reclaimer should schedule during shrink_slab
It has been reported on some laptops that kswapd is consuming large
amounts of CPU and not being scheduled when SLUB is enabled during large
amounts of file copying.  It is expected that this is due to kswapd
missing every cond_resched() point because;

shrink_page_list() calls cond_resched() if inactive pages were isolated
        which in turn may not happen if all_unreclaimable is set in
        shrink_zones(). If for whatver reason, all_unreclaimable is
        set on all zones, we can miss calling cond_resched().

balance_pgdat() only calls cond_resched if the zones are not
        balanced. For a high-order allocation that is balanced, it
        checks order-0 again. During that window, order-0 might have
        become unbalanced so it loops again for order-0 and returns
        that it was reclaiming for order-0 to kswapd(). It can then
        find that a caller has rewoken kswapd for a high-order and
        re-enters balance_pgdat() without ever calling cond_resched().

shrink_slab only calls cond_resched() if we are reclaiming slab
	pages. If there are a large number of direct reclaimers, the
	shrinker_rwsem can be contended and prevent kswapd calling
	cond_resched().

This patch modifies the shrink_slab() case.  If the semaphore is
contended, the caller will still check cond_resched().  After each
successful call into a shrinker, the check for cond_resched() remains in
case one shrinker is particularly slow.

[mgorman@suse.de: preserve call to cond_resched after each call into shrinker]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Colin King <colin.king@canonical.com>
Cc: Raghavendra D Prabhu <raghu.prabhu13@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: <stable@kernel.org>		[2.6.38+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:01 -07:00
..
backing-dev.c Fix common misspellings 2011-03-31 11:26:23 -03:00
bootmem.c crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn 2011-03-23 19:47:19 -07:00
bounce.c
compaction.c mm: compaction: minimise the time IRQs are disabled while isolating pages for migration 2011-03-22 17:44:05 -07:00
debug-pagealloc.c
dmapool.c
fadvise.c
failslab.c
filemap.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-03-24 19:01:30 -07:00
filemap_xip.c
fremap.c
highmem.c
huge_memory.c mm: thp: fix /dev/zero MAP_PRIVATE and vm_flags cleanups 2011-04-28 11:28:20 -07:00
hugetlb.c Merge branch 'master' into for-next 2011-04-26 10:22:59 +02:00
hwpoison-inject.c Fix common misspellings 2011-03-31 11:26:23 -03:00
init-mm.c
internal.h Fix common misspellings 2011-03-31 11:26:23 -03:00
Kconfig
Kconfig.debug mm: debug-pagealloc: fix kconfig dependency warning 2011-03-22 17:44:02 -07:00
kmemcheck.c
kmemleak-test.c
kmemleak.c kmemleak: Do not return a pointer to an object that kmemleak did not get 2011-05-19 17:35:28 +01:00
ksm.c Fix common misspellings 2011-03-31 11:26:23 -03:00
maccess.c
madvise.c
Makefile
memblock.c mm/memblock: properly handle overlaps and fix error path 2011-03-22 17:44:09 -07:00
memcontrol.c Fix common misspellings 2011-03-31 11:26:23 -03:00
memory-failure.c Fix common misspellings 2011-03-31 11:26:23 -03:00
memory.c Don't lock guardpage if the stack is growing up 2011-05-09 16:22:07 -07:00
memory_hotplug.c mm: optimize pfn calculation in online_page() 2011-04-14 16:06:54 -07:00
mempolicy.c mempolicy: remove redundant check in __mpol_equal() 2011-03-22 17:44:04 -07:00
mempool.c
migrate.c Fix common misspellings 2011-03-31 11:26:23 -03:00
mincore.c
mlock.c VM: skip the stack guard page lookup in get_user_pages only for mlock 2011-05-04 21:30:28 -07:00
mm_init.c
mmap.c vm: fix vm_pgoff wrap in upward expansion 2011-05-09 17:52:17 -07:00
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c mm: avoid wrapping vm_pgoff in mremap() 2011-04-07 07:35:51 -07:00
msync.c
nobootmem.c Fix common misspellings 2011-03-31 11:26:23 -03:00
nommu.c NOMMU: implement access_remote_vm 2011-03-29 14:05:12 +01:00
oom_kill.c oom: use pte pages in OOM score 2011-04-28 11:28:21 -07:00
page-writeback.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
page_alloc.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-05-23 09:12:26 -07:00
page_cgroup.c memcg: allocate memory cgroup structures in local nodes 2011-05-11 18:50:45 -07:00
page_io.c
page_isolation.c
pagewalk.c pagewalk: only split huge pages when necessary 2011-03-22 17:44:04 -07:00
percpu-km.c
percpu-vm.c
percpu.c Merge branch 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-05-24 11:53:42 -07:00
pgtable-generic.c
prio_tree.c sanitize <linux/prefetch.h> usage 2011-05-20 12:50:29 -07:00
quicklist.c
readahead.c
rmap.c [S390] merge page_test_dirty and page_clear_dirty 2011-05-23 10:24:31 +02:00
shmem.c tmpfs: fix highmem swapoff crash regression 2011-05-20 16:23:19 -07:00
slab.c sanitize <linux/prefetch.h> usage 2011-05-20 12:50:29 -07:00
slob.c
slub.c slub: Fix double bit unlock in debug mode 2011-05-25 08:38:24 -07:00
sparse-vmemmap.c
sparse.c Fix common misspellings 2011-03-31 11:26:23 -03:00
swap.c mm: check PageUnevictable in lru_deactivate_fn() 2011-05-11 18:50:44 -07:00
swap_state.c
swapfile.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
thrash.c
truncate.c mm: deactivate invalidated pages 2011-03-22 17:44:03 -07:00
util.c Fix common misspellings 2011-03-31 11:26:23 -03:00
vmalloc.c vmalloc: remove confusing comment on vwrite() 2011-03-22 17:44:09 -07:00
vmscan.c mm: vmscan: correctly check if reclaimer should schedule during shrink_slab 2011-05-25 08:39:01 -07:00
vmstat.c mm: add VM counters for transparent hugepages 2011-04-14 16:06:55 -07:00