Messages in this thread Patch in this message | | | Date | Fri, 8 Jun 2012 13:21:26 -0700 (PDT) | From | David Rientjes <> | Subject | [patch for-3.5-rc1] mm, oom: fix badness score underflow |
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If the privileges given to root threads (3% of allowable memory) or a negative value of /proc/pid/oom_score_adj happen to exceed the amount of rss of a thread, its badness score overflows as a result of a7f638f999ff ("mm, oom: normalize oom scores to oom_score_adj scale only for userspace").
Fix this by making the type signed and return 1, meaning the thread is still eligible for kill, if the value is negative.
Reported-by: Dave Jones <davej@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: David Rientjes <rientjes@google.com> --- mm/oom_kill.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -183,7 +183,7 @@ static bool oom_unkillable_task(struct task_struct *p, unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, const nodemask_t *nodemask, unsigned long totalpages) { - unsigned long points; + long points; if (oom_unkillable_task(p, memcg, nodemask)) return 0; @@ -223,7 +223,7 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, * Never return 0 for an eligible task regardless of the root bonus and * oom_score_adj (oom_score_adj can't be OOM_SCORE_ADJ_MIN here). */ - return points ? points : 1; + return points > 0 ? points : 1; } /*
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