]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
oom: don't count on mm-less current process
authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Wed, 11 Feb 2015 23:24:54 +0000 (15:24 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 12 Feb 2015 01:06:00 +0000 (17:06 -0800)
commitd7a94e7e11badf8404d40b41e008c3131a3cebe3
tree0f8a7c3cf1bfd7945740bc67f1607e6923b2186d
parent56873f43abdcd574b25105867a990f067747b2f4
oom: don't count on mm-less current process

out_of_memory() doesn't trigger the OOM killer if the current task is
already exiting or it has fatal signals pending, and gives the task
access to memory reserves instead.  However, doing so is wrong if
out_of_memory() is called by an allocation (e.g. from exit_task_work())
after the current task has already released its memory and cleared
TIF_MEMDIE at exit_mm().  If we again set TIF_MEMDIE to post-exit_mm()
current task, the OOM killer will be blocked by the task sitting in the
final schedule() waiting for its parent to reap it.  It will trigger an
OOM livelock if its parent is unable to reap it due to doing an
allocation and waiting for the OOM killer to kill it.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/oom_kill.c