diff options
author | Oleg Nesterov <oleg@redhat.com> | 2011-07-30 10:35:02 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-08-01 21:24:12 -0400 |
commit | c027a474a68065391c8773f6e83ed5412657e369 (patch) | |
tree | 6d3c8caba5ebf736c3f9ef3cacb708cbdb9869c2 | |
parent | cfe22345ad5ef29e192e157fdc3e17d357e4bc24 (diff) |
oom: task->mm == NULL doesn't mean the memory was freed
exit_mm() sets ->mm == NULL then it does mmput()->exit_mmap() which
frees the memory.
However select_bad_process() checks ->mm != NULL before TIF_MEMDIE,
so it continues to kill other tasks even if we have the oom-killed
task freeing its memory.
Change select_bad_process() to check ->mm after TIF_MEMDIE, but skip
the tasks which have already passed exit_notify() to ensure a zombie
with TIF_MEMDIE set can't block oom-killer. Alternatively we could
probably clear TIF_MEMDIE after exit_mmap().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/oom_kill.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index eafff89b3dd6..626303b52f3c 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c | |||
@@ -303,7 +303,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints, | |||
303 | do_each_thread(g, p) { | 303 | do_each_thread(g, p) { |
304 | unsigned int points; | 304 | unsigned int points; |
305 | 305 | ||
306 | if (!p->mm) | 306 | if (p->exit_state) |
307 | continue; | 307 | continue; |
308 | if (oom_unkillable_task(p, mem, nodemask)) | 308 | if (oom_unkillable_task(p, mem, nodemask)) |
309 | continue; | 309 | continue; |
@@ -319,6 +319,8 @@ static struct task_struct *select_bad_process(unsigned int *ppoints, | |||
319 | */ | 319 | */ |
320 | if (test_tsk_thread_flag(p, TIF_MEMDIE)) | 320 | if (test_tsk_thread_flag(p, TIF_MEMDIE)) |
321 | return ERR_PTR(-1UL); | 321 | return ERR_PTR(-1UL); |
322 | if (!p->mm) | ||
323 | continue; | ||
322 | 324 | ||
323 | if (p->flags & PF_EXITING) { | 325 | if (p->flags & PF_EXITING) { |
324 | /* | 326 | /* |