diff options
| author | David Rientjes <rientjes@google.com> | 2012-06-20 12:52:58 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-20 14:39:35 -0700 |
| commit | 61eafb00d55dfbccdfce543c6b60e369ff4f8f18 (patch) | |
| tree | e2be309a7412de35dd8414ea030b6650d2ea8b75 /mm | |
| parent | fbb24a3a915f105016f1c828476be11aceac8504 (diff) | |
| download | lwn-61eafb00d55dfbccdfce543c6b60e369ff4f8f18.tar.gz lwn-61eafb00d55dfbccdfce543c6b60e369ff4f8f18.zip | |
mm, oom: fix and cleanup oom score calculations
The divide in p->signal->oom_score_adj * totalpages / 1000 within
oom_badness() was causing an overflow of the signed long data type.
This adds both the root bias and p->signal->oom_score_adj before doing the
normalization which fixes the issue and also cleans up the calculation.
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.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 | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 416637f0e924..77775138e930 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -184,6 +184,7 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, const nodemask_t *nodemask, unsigned long totalpages) { long points; + long adj; if (oom_unkillable_task(p, memcg, nodemask)) return 0; @@ -192,7 +193,8 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, if (!p) return 0; - if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { + adj = p->signal->oom_score_adj; + if (adj == OOM_SCORE_ADJ_MIN) { task_unlock(p); return 0; } @@ -210,14 +212,11 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, * implementation used by LSMs. */ if (has_capability_noaudit(p, CAP_SYS_ADMIN)) - points -= 30 * totalpages / 1000; + adj -= 30; - /* - * /proc/pid/oom_score_adj ranges from -1000 to +1000 such that it may - * either completely disable oom killing or always prefer a certain - * task. - */ - points += p->signal->oom_score_adj * totalpages / 1000; + /* Normalize to oom_score_adj units */ + adj *= totalpages / 1000; + points += adj; /* * Never return 0 for an eligible task regardless of the root bonus and |