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| author | KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> | 2010-08-09 17:19:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-09 20:45:02 -0700 |
| commit | cef1d3523d33ebc35fc29e454b1f4bab953fabbf (patch) | |
| tree | 3688cf9e7c3b1bd4e1d473d79fd1a959bd4306fb /mm | |
| parent | 93b43fa55088fe977503a156d1097cc2055449a2 (diff) | |
| download | kernel_samsung_crespo-cef1d3523d33ebc35fc29e454b1f4bab953fabbf.zip kernel_samsung_crespo-cef1d3523d33ebc35fc29e454b1f4bab953fabbf.tar.gz kernel_samsung_crespo-cef1d3523d33ebc35fc29e454b1f4bab953fabbf.tar.bz2 | |
oom: multi threaded process coredump don't make deadlock
Oleg pointed out current PF_EXITING check is wrong. Because PF_EXITING
is per-thread flag, not per-process flag. He said,
Two threads, group-leader L and its sub-thread T. T dumps the code.
In this case both threads have ->mm != NULL, L has PF_EXITING.
The first problem is, select_bad_process() always return -1 in this
case (even if the caller is T, this doesn't matter).
The second problem is that we should add TIF_MEMDIE to T, not L.
I think we can remove this dubious PF_EXITING check. but as first step,
This patch add the protection of multi threaded issue.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: 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>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/oom_kill.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 31bd0c3..0a4ca8a 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -360,7 +360,7 @@ static struct task_struct *select_bad_process(unsigned long *ppoints, * the process of exiting and releasing its resources. * Otherwise we could get an easy OOM deadlock. */ - if ((p->flags & PF_EXITING) && p->mm) { + if (thread_group_empty(p) && (p->flags & PF_EXITING) && p->mm) { if (p != current) return ERR_PTR(-1UL); |