diff options
author | Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> | 2009-01-08 05:08:29 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-08 19:31:09 +0300 |
commit | 7f4d454dee2e0bdd21bafd413d1c53e443a26540 (patch) | |
tree | abf54c2bd7c91fe09685e42b3a92d84679403058 /scripts | |
parent | a5e924f5f8abf97944e625d74967cc9452cfbce8 (diff) | |
download | linux-7f4d454dee2e0bdd21bafd413d1c53e443a26540.tar.xz |
memcg: avoid deadlock caused by race between oom and cpuset_attach
mpol_rebind_mm(), which can be called from cpuset_attach(), does
down_write(mm->mmap_sem). This means down_write(mm->mmap_sem) can be
called under cgroup_mutex.
OTOH, page fault path does down_read(mm->mmap_sem) and calls
mem_cgroup_try_charge_xxx(), which may eventually calls
mem_cgroup_out_of_memory(). And mem_cgroup_out_of_memory() calls
cgroup_lock(). This means cgroup_lock() can be called under
down_read(mm->mmap_sem).
If those two paths race, deadlock can happen.
This patch avoid this deadlock by:
- remove cgroup_lock() from mem_cgroup_out_of_memory().
- define new mutex (memcg_tasklist) and serialize mem_cgroup_move_task()
(->attach handler of memory cgroup) and mem_cgroup_out_of_memory.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'scripts')
0 files changed, 0 insertions, 0 deletions