linux/mm
zhong jiang 956e1e405c mm,ksm: fix endless looping in allocating memory when ksm enable
[ Upstream commit 5b398e416e ]

I hit the following hung task when runing a OOM LTP test case with 4.1
kernel.

Call trace:
[<ffffffc000086a88>] __switch_to+0x74/0x8c
[<ffffffc000a1bae0>] __schedule+0x23c/0x7bc
[<ffffffc000a1c09c>] schedule+0x3c/0x94
[<ffffffc000a1eb84>] rwsem_down_write_failed+0x214/0x350
[<ffffffc000a1e32c>] down_write+0x64/0x80
[<ffffffc00021f794>] __ksm_exit+0x90/0x19c
[<ffffffc0000be650>] mmput+0x118/0x11c
[<ffffffc0000c3ec4>] do_exit+0x2dc/0xa74
[<ffffffc0000c46f8>] do_group_exit+0x4c/0xe4
[<ffffffc0000d0f34>] get_signal+0x444/0x5e0
[<ffffffc000089fcc>] do_signal+0x1d8/0x450
[<ffffffc00008a35c>] do_notify_resume+0x70/0x78

The oom victim cannot terminate because it needs to take mmap_sem for
write while the lock is held by ksmd for read which loops in the page
allocator

ksm_do_scan
	scan_get_next_rmap_item
		down_read
		get_next_rmap_item
			alloc_rmap_item   #ksmd will loop permanently.

There is no way forward because the oom victim cannot release any memory
in 4.1 based kernel.  Since 4.6 we have the oom reaper which would solve
this problem because it would release the memory asynchronously.
Nevertheless we can relax alloc_rmap_item requirements and use
__GFP_NORETRY because the allocation failure is acceptable as ksm_do_scan
would just retry later after the lock got dropped.

Such a patch would be also easy to backport to older stable kernels which
do not have oom_reaper.

While we are at it add GFP_NOWARN so the admin doesn't have to be alarmed
by the allocation failure.

Link: http://lkml.kernel.org/r/1474165570-44398-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Suggested-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
History 2016-12-23 09:41:22 -05:00
..
backing-dev.c Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block 2014-10-18 11:53:51 -07:00
balloon_compaction.c virtio_balloon: fix race between migration and ballooning 2016-02-09 22:56:37 -05:00
bootmem.c mm: page_alloc: pass PFN to __free_pages_bootmem 2016-04-18 08:49:40 -04:00
cleancache.c mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE 2014-01-23 16:36:50 -08:00
cma.c mm/CMA: fix boot regression due to physical address of high_memory 2015-01-08 10:30:28 -08:00
compaction.c mm, compaction: abort free scanner if split fails 2016-07-12 08:47:12 -04:00
debug-pagealloc.c mm, x86: Remove debug_pagealloc_enabled 2011-12-06 09:24:07 +01:00
debug.c mm/debug.c: use pr_emerg() 2014-10-09 22:25:59 -04:00
dmapool.c mm/dmapool.c: fixed a brace coding style issue 2014-10-09 22:26:00 -04:00
early_ioremap.c mm: create generic early_ioremap() support 2014-04-07 16:36:15 -07:00
fadvise.c teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long 2013-03-03 22:46:22 -05:00
failslab.c switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
filemap.c mm: make sendfile(2) killable 2015-11-15 12:51:48 -05:00
filemap_xip.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
fremap.c mm: mark remap_file_pages() syscall as deprecated 2014-06-06 16:08:17 -07:00
frontswap.c mm: frontswap: invalidate expired data on a dup-store failure 2014-12-02 17:32:07 -08:00
gup.c mm: remove gup_flags FOLL_WRITE games from __get_user_pages() 2016-10-22 15:48:09 -04:00
highmem.c mm/highmem: make kmap cache coloring aware 2014-08-06 18:01:22 -07:00
huge_memory.c mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check 2016-05-17 14:51:57 -04:00
hugetlb.c mm/hugetlb: avoid soft lockup in set_max_huge_pages() 2016-08-22 12:23:27 -04:00
hugetlb_cgroup.c hugetlb_cgroup: use lockdep_assert_held rather than spin_is_locked 2014-08-29 16:28:16 -07:00
hwpoison-inject.c mm/hwpoison-inject.c: remove unnecessary null test before debugfs_remove_recursive 2014-08-06 18:01:19 -07:00
init-mm.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
internal.h mm: use 'unsigned int' for page order 2016-04-18 08:49:40 -04:00
interval_tree.c mm: convert a few VM_BUG_ON callers to VM_BUG_ON_VMA 2014-10-09 22:25:57 -04:00
iov_iter.c Fix thinko in iov_iter_single_seg_count 2014-11-13 13:28:55 -05:00
Kconfig mm/balloon_compaction: add vmstat counters and kpageflags bit 2014-10-09 22:26:01 -04:00
Kconfig.debug mm: more intensive memory corruption debugging 2012-01-10 16:30:42 -08:00
kmemcheck.c mm/slab_common: move kmem_cache definition to internal header 2014-10-09 22:25:50 -04:00
kmemleak-test.c mm/kmemleak-test.c: use pr_fmt for logging 2014-06-06 16:08:18 -07:00
kmemleak.c mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc() 2015-07-05 10:12:51 -04:00
ksm.c mm,ksm: fix endless looping in allocating memory when ksm enable 2016-12-23 09:41:22 -05:00
list_lru.c mm: keep page cache radix tree nodes in check 2014-04-03 16:21:01 -07:00
maccess.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
madvise.c mm: update the description for madvise_remove 2014-08-06 18:01:18 -07:00
Makefile Fixup for 3.18: use PATCHv2 of "mm: Support compiling out madvise and fadvise" 2014-10-12 09:21:57 -04:00
memblock.c mm: page_alloc: pass PFN to __free_pages_bootmem 2016-04-18 08:49:40 -04:00
memcontrol.c memcg: only free spare array when readers are done 2016-02-09 22:57:10 -05:00
memory-failure.c mm: soft-offline: check return value in second __get_any_page() call 2016-02-09 22:57:09 -05:00
memory.c mm: thp: fix SMP race condition between THP page fault and MADV_DONTNEED 2016-03-11 09:45:21 -05:00
memory_hotplug.c mm/memory_hotplug.c: set zone->wait_table to null after freeing it 2015-07-03 12:34:45 -04:00
mempolicy.c mm, numa: really disable NUMA balancing by default on single node machines 2015-06-10 13:42:34 -04:00
mempool.c mm/mempool.c: update the kmemleak stack trace for mempool allocations 2014-06-06 16:08:17 -07:00
migrate.c mm: Export migrate_page_move_mapping and migrate_page_copy 2016-07-12 08:47:00 -04:00
mincore.c mm + fs: prepare for non-page entries in page cache radix trees 2014-04-03 16:21:00 -07:00
mlock.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:44:12 +02:00
mm_init.c mm: bring back /sys/kernel/mm 2014-01-27 21:02:39 -08:00
mmap.c mm: replace vma_lock_anon_vma with anon_vma_lock_read/write 2016-02-15 15:42:41 -05:00
mmu_context.c sched/mm: call finish_arch_post_lock_switch in idle_task_exit and use_mm 2014-02-21 08:50:17 +01:00
mmu_notifier.c kvm: Fix page ageing bugs 2014-09-24 14:07:58 +02:00
mmzone.c mm: numa: Change page last {nid,pid} into {cpu,pid} 2013-10-09 14:47:45 +02:00
mprotect.c mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared 2014-10-14 02:18:28 +02:00
mremap.c mm/mremap.c: use linux headers 2014-10-09 22:26:00 -04:00
msync.c msync: fix incorrect fstart calculation 2014-07-03 09:21:53 -07:00
nobootmem.c mm: page_alloc: pass PFN to __free_pages_bootmem 2016-04-18 08:49:40 -04:00
nommu.c mm/nommu.c: fix arithmetic overflow in __vm_enough_memory() 2015-03-14 15:37:16 -04:00
oom_kill.c OOM, PM: OOM killed task shouldn't escape PM suspend 2014-10-21 23:44:21 +02:00
page-writeback.c writeback: use |1 instead of +1 to protect against div by zero 2015-05-23 15:52:00 -04:00
page_alloc.c mm/page_alloc: prevent merging between isolated and other pageblocks 2016-04-18 08:49:41 -04:00
page_cgroup.c cgroup/kmemleak: add kmemleak_free() for cgroup deallocations. 2014-10-29 16:33:13 -07:00
page_io.c fix __swap_writepage() compile failure on old gcc versions 2014-06-14 19:30:48 -05:00
page_isolation.c mm: fix invalid node in alloc_migrate_target() 2016-07-12 08:47:24 -04:00
pagewalk.c mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range 2015-02-11 15:00:53 +08:00
percpu-km.c percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated 2014-09-02 14:46:05 -04:00
percpu-vm.c percpu: move region iterations out of pcpu_[de]populate_chunk() 2014-09-02 14:46:02 -04:00
percpu.c percpu: fix synchronization between synchronous map extension and chunk destruction 2016-07-11 10:20:46 -04:00
pgtable-generic.c mm: actually clear pmd_numa before invalidating 2014-08-29 16:28:15 -07:00
process_vm_access.c ptrace: use fsuid, fsgid, effective creds for fs access checks 2016-04-12 17:06:22 -04:00
quicklist.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
readahead.c mm/readahead.c: remove unused file_ra_state from count_history_pages 2014-08-06 18:01:15 -07:00
rmap.c mm: fix anon_vma->degree underflow in anon_vma endless growing prevention 2015-04-24 17:13:38 -04:00
shmem.c tmpfs: fix regression hang in fallocate undo 2016-07-12 08:48:38 -04:00
slab.c mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1) 2015-10-27 22:14:30 -04:00
slab.h mm/slab: use percpu allocator for cpu cache 2014-10-09 22:25:51 -04:00
slab_common.c mm/slab: fix unalignment problem on Malta with EVA due to slab merge 2014-11-13 16:17:05 -08:00
slob.c mm/sl[ao]b: always track caller in kmalloc_(node_)track_caller() 2014-10-09 22:25:50 -04:00
slub.c mm/slab_common: commonize slab merge logic 2014-10-09 22:25:51 -04:00
sparse-vmemmap.c mm/sparse: use memblock apis for early memory allocations 2014-01-21 16:19:47 -08:00
sparse.c mm: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:35:54 -07:00
swap.c 4.1.28 Fix bad backport of 8f182270df "mm/swap.c: flush lru pvecs on compound page arrival" 2016-07-20 11:35:52 -04:00
swap_state.c mm: memcontrol: do not kill uncharge batching in free_pages_and_swap_cache 2014-10-09 22:25:59 -04:00
swapfile.c mm: memcontrol: rewrite uncharge API 2014-08-08 15:57:17 -07:00
truncate.c mm: rename deactivate_page to deactivate_file_page 2016-07-12 08:47:10 -04:00
util.c proc/maps: make vm_is_stack() logic namespace-friendly 2014-10-09 22:25:50 -04:00
vmacache.c mm,vmacache: optimize overflow system-wide flushing 2014-06-04 16:53:57 -07:00
vmalloc.c mm/vmalloc.c: use seq_open_private() instead of seq_open() 2014-10-09 22:25:56 -04:00
vmpressure.c mm/vmpressure.c: fix race in vmpressure_work_fn() 2014-12-02 17:32:07 -08:00
vmscan.c vmscan: fix increasing nr_isolated incurred by putback unevictable pages 2015-10-07 10:18:57 -04:00
vmstat.c vmstat: do not use deferrable delayed work for vmstat_update 2015-03-23 21:02:53 -04:00
workingset.c mm: keep page cache radix tree nodes in check 2014-04-03 16:21:01 -07:00
zbud.c zbud: avoid accessing last unused freelist 2014-10-09 22:26:03 -04:00
zpool.c mm/zpool: use prefixed module loading 2014-08-29 16:28:16 -07:00
zsmalloc.c zsmalloc: simplify init_zspage free obj linking 2014-10-09 22:26:03 -04:00
zswap.c mm/zswap.c: add __init to zswap_entry_cache_destroy() 2014-08-08 15:57:18 -07:00