linux-hardened/mm
Daisuke Nishimura 9ab322caa3 memcg: remove memcg_tasklist
memcg_tasklist was introduced at commit 7f4d454d(memcg: avoid deadlock
caused by race between oom and cpuset_attach) instead of cgroup_mutex to
fix a deadlock problem.  The cgroup_mutex, which was removed by the
commit, in mem_cgroup_out_of_memory() was originally introduced at commit
c7ba5c9e (Memory controller: OOM handling).

IIUC, the intention of this cgroup_mutex was to prevent task move during
select_bad_process() so that situations like below can be avoided.

  Assume cgroup "foo" has exceeded its limit and is about to trigger oom.
  1. Process A, which has been in cgroup "baa" and uses large memory, is just
     moved to cgroup "foo". Process A can be the candidates for being killed.
  2. Process B, which has been in cgroup "foo" and uses large memory, is just
     moved from cgroup "foo". Process B can be excluded from the candidates for
     being killed.

But these race window exists anyway even if we hold a lock, because
__mem_cgroup_try_charge() decides wether it should trigger oom or not
outside of the lock.  So the original cgroup_mutex in
mem_cgroup_out_of_memory and thus current memcg_tasklist has no use.  And
IMHO, those races are not so critical for users.

This patch removes it and make codes simpler.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: 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>
2009-12-16 07:20:07 -08:00
..
backing-dev.c flusher: Fix PF_FROZEN race 2009-12-03 13:49:43 +01:00
bootmem.c mm/bootmem.c: properly __init-annotate helper functions 2009-12-15 08:53:20 -08:00
bounce.c block: remove some includings of blktrace_api.h 2009-06-16 11:19:36 +02:00
debug-pagealloc.c generic debug pagealloc 2009-04-01 08:59:13 -07:00
dmapool.c dmapools: protect page_list walk in show_pools() 2009-06-30 18:56:00 -07:00
fadvise.c readahead: move max_sane_readahead() calls into force_page_cache_readahead() 2009-06-16 19:47:28 -07:00
failslab.c kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c 2009-04-03 12:23:01 +02:00
filemap.c kill wait_on_page_writeback_range 2009-12-10 15:02:50 +01:00
filemap_xip.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
fremap.c Do not account for the address space used by hugetlbfs using VM_ACCOUNT 2009-02-10 10:48:42 -08:00
highmem.c highmem: Fix debug_kmap_atomic() to also handle KM_IRQ_PTE, KM_NMI, and KM_NMI_PTE 2009-11-10 04:15:47 +01:00
hugetlb.c hugetlb: abort a hugepage pool resize if a signal is pending 2009-12-15 08:53:24 -08:00
hwpoison-inject.c HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs 2009-09-16 11:50:17 +02:00
init-mm.c mm: consolidate init_mm definition 2009-06-16 19:47:28 -07:00
internal.h mm: remove unevictable_migrate_page function 2009-12-15 08:53:23 -08:00
Kconfig ksm: remove unswappable max_kernel_pages 2009-12-15 08:53:20 -08:00
Kconfig.debug trivial: improve help text for mm debug config options 2009-09-21 15:14:57 +02:00
kmemcheck.c kmemcheck: add hooks for the page allocator 2009-06-15 15:48:33 +02:00
kmemleak-test.c percpu: clean up percpu variable definitions 2009-06-24 15:13:48 +09:00
kmemleak.c tree-wide: fix typos "aquire" -> "acquire", "cumsumed" -> "consumed" 2009-11-09 09:40:57 +01:00
ksm.c ksm: remove unswappable max_kernel_pages 2009-12-15 08:53:20 -08:00
maccess.c [S390] maccess: add weak attribute to probe_kernel_write 2009-06-12 10:27:37 +02:00
madvise.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2009-09-24 07:53:22 -07:00
Makefile percpu: kill legacy percpu allocator 2009-10-02 13:29:29 +09:00
memcontrol.c memcg: remove memcg_tasklist 2009-12-16 07:20:07 -08:00
memory-failure.c mm: CONFIG_MMU for PG_mlocked 2009-12-15 08:53:17 -08:00
memory.c memcg: coalesce uncharge during unmap/truncate 2009-12-16 07:20:07 -08:00
memory_hotplug.c mm: fix section mismatch in memory_hotplug.c 2009-12-15 08:53:20 -08:00
mempolicy.c ksm: memory hotremove migration only 2009-12-15 08:53:20 -08:00
mempool.c mm: remove broken 'kzalloc' mempool 2009-09-22 07:17:35 -07:00
migrate.c mm: remove unevictable_migrate_page function 2009-12-15 08:53:23 -08:00
mincore.c mm: hugetlb: fix hugepage memory leak in mincore() 2009-12-15 08:53:24 -08:00
mlock.c mlock: replace stale comments in munlock_vma_page() 2009-12-15 08:53:23 -08:00
mm_init.c mm: mminit_loglevel cannot be __meminitdata anymore 2008-08-20 15:40:30 -07:00
mmap.c mm: uncached vma support with writenotify 2009-12-15 08:53:21 -08:00
mmu_context.c mm: reduce atomic use on use_mm fast path 2009-09-22 07:17:42 -07:00
mmu_notifier.c ksm: add mmu_notifier set_pte_at_notify() 2009-09-22 07:17:31 -07:00
mmzone.c [ARM] Double check memmap is actually valid with a memmap has unexpected holes V2 2009-05-18 11:22:24 +01:00
mprotect.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
mremap.c Take arch_mmap_check() into get_unmapped_area() 2009-12-11 06:44:58 -05:00
msync.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
nommu.c nommu: fix malloc performance by adding uninitialized flag 2009-12-15 08:53:24 -08:00
oom_kill.c memcg: avoid oom-killing innocent task in case of use_hierarchy 2009-12-16 07:20:07 -08:00
page-writeback.c writeback: remove unused nonblocking and congestion checks 2009-12-03 13:54:25 +01:00
page_alloc.c oom-kill: fix NUMA constraint check with nodemask 2009-12-16 07:19:57 -08:00
page_cgroup.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
page_io.c swap: rework map_swap_page() again 2009-12-15 08:53:16 -08:00
page_isolation.c memory hotplug: fix page_zone() calculation in test_pages_isolated() 2008-11-06 15:41:19 -08:00
pagewalk.c mm hugetlb: add hugepage support to pagemap 2009-12-15 08:53:24 -08:00
percpu.c Merge branch 'for-linus' into for-next 2009-12-08 10:02:12 +09:00
prio_tree.c
quicklist.c cpumask: use new-style cpumask ops in mm/quicklist. 2009-09-24 09:34:52 +09:30
readahead.c readahead: introduce context readahead algorithm 2009-06-16 19:47:30 -07:00
rmap.c memcg: make memcg's file mapped consistent with global VM 2009-12-16 07:20:07 -08:00
shmem.c swap_info: note SWAP_MAP_SHMEM 2009-12-15 08:53:16 -08:00
shmem_acl.c shmfs: use 'check_acl' instead of 'permission' 2009-09-08 11:08:46 -07:00
slab.c Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-14 10:13:22 -08:00
slob.c slab: remove duplicate kmem_cache_init_late() declarations 2009-08-06 11:36:25 +03:00
slub.c Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-14 10:13:22 -08:00
sparse-vmemmap.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
sparse.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
swap.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
swap_state.c mm: add_to_swap_cache() does not return -EEXIST 2009-09-22 07:17:35 -07:00
swapfile.c ksm: let shared pages be swappable 2009-12-15 08:53:19 -08:00
thrash.c mm: pass mm to grab_swap_token 2009-06-23 12:50:05 -07:00
truncate.c memcg: coalesce uncharge during unmap/truncate 2009-12-16 07:20:07 -08:00
util.c fix a struct file leak in do_mmap_pgoff() 2009-12-11 06:44:57 -05:00
vmalloc.c vmalloc(): adjust gfp mask passed on nested vmalloc() invocation 2009-12-15 08:53:13 -08:00
vmscan.c vmscan: simplify code 2009-12-15 08:53:21 -08:00
vmstat.c vmscan: stop kswapd waiting on congestion when the min watermark is not being met 2009-12-15 08:53:16 -08:00