mm, oom: fix potential killing of thread that is disabled from oom killing
/proc/sys/vm/oom_kill_allocating_task will immediately kill current when
the oom killer is called to avoid a potentially expensive tasklist scan
for large systems.
Currently, however, it is not checking current's oom_score_adj value which
may be OOM_SCORE_ADJ_MIN, meaning that it has been disabled from oom
killing.
This patch avoids killing current in such a condition and simply falls
back to the tasklist scan since memory still needs to be freed.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index e8ab3df..50e7437 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -719,9 +719,9 @@
check_panic_on_oom(constraint, gfp_mask, order, mpol_mask);
read_lock(&tasklist_lock);
- if (sysctl_oom_kill_allocating_task &&
+ if (sysctl_oom_kill_allocating_task && current->mm &&
!oom_unkillable_task(current, NULL, nodemask) &&
- current->mm) {
+ current->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) {
oom_kill_process(current, gfp_mask, order, 0, totalpages, NULL,
nodemask,
"Out of memory (oom_kill_allocating_task)");
