linux/mm
Johannes Weiner f0fdc5e8e6 vmscan: fix zone shrinking exit when scan work is done
Commit 3e7d344970 ("mm: vmscan: reclaim order-0 and use compaction
instead of lumpy reclaim") introduced an indefinite loop in
shrink_zone().

It meant to break out of this loop when no pages had been reclaimed and
not a single page was even scanned.  The way it would detect the latter
is by taking a snapshot of sc->nr_scanned at the beginning of the
function and comparing it against the new sc->nr_scanned after the scan
loop.  But it would re-iterate without updating that snapshot, looping
forever if sc->nr_scanned changed at least once since shrink_zone() was
invoked.

This is not the sole condition that would exit that loop, but it
requires other processes to change the zone state, as the reclaimer that
is stuck obviously can not anymore.

This is only happening for higher-order allocations, where reclaim is
run back to back with compaction.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Michal Hocko <mhocko@suse.cz>
Tested-by: Kent Overstreet<kent.overstreet@gmail.com>
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-11 16:12:20 -08:00
..
backing-dev.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-10-26 17:58:44 -07:00
bootmem.c x86, memblock: Replace e820_/_early string with memblock_ 2010-08-27 11:13:47 -07:00
bounce.c bounce: call flush_dcache_page() after bounce_copy_vec() 2010-09-09 18:57:25 -07:00
compaction.c mm: compaction: prevent division-by-zero during user-requested compaction 2011-01-20 17:02:05 -08:00
debug-pagealloc.c
dmapool.c mm/dmapool.c: use TASK_UNINTERRUPTIBLE in dma_pool_alloc() 2011-01-13 17:32:48 -08:00
fadvise.c readahead: introduce FMODE_RANDOM for POSIX_FADV_RANDOM 2010-03-06 11:26:25 -08:00
failslab.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
filemap_xip.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
filemap.c mm: remove likely() from grab_cache_page_write_begin() 2011-01-13 17:32:36 -08:00
fremap.c Avoid pgoff overflow in remap_file_pages 2010-09-25 09:34:58 -07:00
highmem.c mm,x86: fix kmap_atomic_push vs ioremap_32.c 2010-10-27 18:03:05 -07:00
huge_memory.c thp: fix the wrong reported address of hwpoisoned hugepages 2011-02-02 16:03:19 -08:00
hugetlb.c hugetlb: fix handling of parse errors in sysfs 2011-01-13 17:32:49 -08:00
hwpoison-inject.c HWPOISON, hugetlb: support hwpoison injection for hugepage 2010-08-11 09:23:11 +02:00
init-mm.c mm: provide init_mm mm_context initializer 2010-08-09 20:44:54 -07:00
internal.h Revert "mm: batch activate_page() to reduce lock contention" 2011-01-17 14:42:19 -08:00
Kconfig mm: compaction: don't depend on HUGETLB_PAGE 2011-01-26 10:50:02 +10:00
Kconfig.debug trivial: improve help text for mm debug config options 2009-09-21 15:14:57 +02:00
kmemcheck.c kmemcheck: Fix build errors due to missing slab.h 2010-03-30 22:02:32 +09:00
kmemleak-test.c kmemleak: remove memset by using kzalloc 2011-01-27 18:31:51 +00:00
kmemleak.c kmemleak: Allow kmemleak metadata allocations to fail 2011-01-27 18:32:06 +00:00
ksm.c ksm: drain pagevecs to lru 2011-01-13 17:32:49 -08:00
maccess.c MN10300: Save frame pointer in thread_info struct rather than global var 2010-10-27 17:29:01 +01:00
madvise.c thp: khugepaged: make khugepaged aware about madvise 2011-01-13 17:32:47 -08:00
Makefile thp: transparent hugepage core 2011-01-13 17:32:42 -08:00
memblock.c memblock: don't adjust size in memblock_find_base() 2011-02-11 16:12:20 -08:00
memcontrol.c memcg: fix event counting breakage from recent THP update 2011-02-02 16:03:19 -08:00
memory_hotplug.c Merge branch 'slub/hotplug' into slab/urgent 2011-01-15 13:28:17 +02:00
memory-failure.c thp: fix unsuitable behavior for hwpoisoned tail page 2011-02-02 16:03:19 -08:00
memory.c mlock: do not munlock pages in __do_fault() 2011-02-11 16:12:20 -08:00
mempolicy.c thp: add numa awareness to hugepage allocations 2011-01-13 17:32:45 -08:00
mempool.c mm: remove broken 'kzalloc' mempool 2009-09-22 07:17:35 -07:00
migrate.c mm/migration: fix page corruption during hugepage migration 2011-02-02 16:03:18 -08:00
mincore.c thp: mincore transparent hugepage support 2011-01-13 17:32:44 -08:00
mlock.c mlock: operate on any regions with protection != PROT_NONE 2011-02-02 10:20:50 +11:00
mm_init.c
mmap.c brk: fix min_brk lower bound computation for COMPAT_BRK 2011-01-13 17:32:48 -08:00
mmu_context.c exit: fix oops in sync_mm_rss 2010-03-24 16:31:21 -07:00
mmu_notifier.c thp: mmu_notifier_test_young 2011-01-13 17:32:46 -08:00
mmzone.c mm: page allocator: adjust the per-cpu counter threshold when memory is low 2011-01-13 17:32:31 -08:00
mprotect.c thp: mprotect: transparent huge page support 2011-01-13 17:32:44 -08:00
mremap.c thp: split_huge_page_mm/vma 2011-01-13 17:32:41 -08:00
msync.c sanitize vfs_fsync calling conventions 2010-05-21 18:31:21 -04:00
nommu.c mlock: do not hold mmap_sem for extended periods of time 2011-01-13 17:32:36 -08:00
oom_kill.c oom: kill all threads sharing oom killed task's mm 2010-10-26 16:52:05 -07:00
page_alloc.c mm: clear pages_scanned only if draining a pcp adds pages to the buddy allocator 2011-01-26 10:50:01 +10:00
page_cgroup.c kmemleak: Annotate false positive in init_section_page_cgroup() 2010-07-19 11:54:14 +01:00
page_io.c block: unify flags for struct bio and struct request 2010-08-07 18:20:39 +02:00
page_isolation.c mm: page_isolation: codeclean fix comment and rm unneeded val init 2010-10-26 16:52:11 -07:00
page-writeback.c writeback: avoid unnecessary determine_dirtyable_memory call 2011-01-13 17:32:38 -08:00
pagewalk.c thp: split_huge_page_mm/vma 2011-01-13 17:32:41 -08:00
percpu-km.c percpu: clear memory allocated with the km allocator 2010-10-02 10:28:42 +03:00
percpu-vm.c mm: remove gfp mask from pcpu_get_vm_areas 2011-01-13 17:32:34 -08:00
percpu.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-01-13 10:05:56 -08:00
pgtable-generic.c mm/pgtable-generic.c: fix CONFIG_SWAP=n build 2011-01-26 10:49:58 +10:00
prio_tree.c
quicklist.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
readahead.c readahead.c: fix comment 2010-05-25 08:07:00 -07:00
rmap.c memcg: create extensible page stat update routines 2011-01-13 17:32:50 -08:00
shmem.c fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
slab.c mm/slab.c: make local symbols static 2011-01-15 13:28:36 +02:00
slob.c kernel: kmem_ptr_validate considered harmful 2011-01-07 17:50:16 +11:00
slub.c Merge branch 'slub/hotplug' into slab/urgent 2011-01-15 13:28:17 +02:00
sparse-vmemmap.c tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
sparse.c thp: remove PG_buddy 2011-01-13 17:32:43 -08:00
swap_state.c thp: split_huge_page paging 2011-01-13 17:32:41 -08:00
swap.c Revert "mm: simplify code of swap.c" 2011-01-17 14:42:34 -08:00
swapfile.c thp: split_huge_page paging 2011-01-13 17:32:41 -08:00
thrash.c mm: pass mm to grab_swap_token 2009-06-23 12:50:05 -07:00
truncate.c mm: fix truncate_setsize() comment 2011-01-20 17:02:06 -08:00
util.c kernel: kmem_ptr_validate considered harmful 2011-01-07 17:50:16 +11:00
vmalloc.c Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2011-01-13 20:15:35 -08:00
vmscan.c vmscan: fix zone shrinking exit when scan work is done 2011-02-11 16:12:20 -08:00
vmstat.c thp: transparent hugepage vmstat 2011-01-13 17:32:43 -08:00