diff options
| author | Michal Hocko <mhocko@suse.com> | 2016-03-25 14:20:36 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-25 16:37:42 -0700 |
| commit | 855b018325737f7691f9b7d86339df40aa4e47c3 (patch) | |
| tree | 53593c573d50f6ae6f46d05a8339528f44b99b5b | |
| parent | 03049269de433cb5fe2859be9ae4469ceb1163ed (diff) | |
oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task
Tetsuo has reported that oom_kill_allocating_task=1 will cause
oom_reaper_list corruption because oom_kill_process doesn't follow
standard OOM exclusion (aka ignores TIF_MEMDIE) and allows to enqueue
the same task multiple times - e.g. by sacrificing the same child
multiple times.
This patch fixes the issue by introducing a new MMF_OOM_KILLED mm flag
which is set in oom_kill_process atomically and oom reaper is disabled
if the flag was already set.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | mm/oom_kill.c | 6 |
2 files changed, 7 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 788f223f8f8f..c2d2d7c5d463 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -512,6 +512,8 @@ static inline int get_dumpable(struct mm_struct *mm) #define MMF_HAS_UPROBES 19 /* has uprobes */ #define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */ +#define MMF_OOM_KILLED 21 /* OOM killer has chosen this mm */ + #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK) struct sighand_struct { diff --git a/mm/oom_kill.c b/mm/oom_kill.c index f6d4ae9f1c69..1a21819a8e5e 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -680,7 +680,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, unsigned int victim_points = 0; static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); - bool can_oom_reap = true; + bool can_oom_reap; /* * If the task is already exiting, don't alarm the sysadmin or kill @@ -742,6 +742,10 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, /* Get a reference to safely compare mm after task_unlock(victim) */ mm = victim->mm; atomic_inc(&mm->mm_count); + + /* Make sure we do not try to oom reap the mm multiple times */ + can_oom_reap = !test_and_set_bit(MMF_OOM_KILLED, &mm->flags); + /* * We should send SIGKILL before setting TIF_MEMDIE in order to prevent * the OOM victim from depleting the memory reserves from the user |