From 8c5cd6f3a1721085652da204d454af4f8b92eda2 Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Mon, 21 Sep 2009 17:03:15 -0700 Subject: [PATCH] oom: oom_kill doesn't kill vfork parent (or child) Current oom_kill doesn't only kill the victim process, but also kill all thas shread the same mm. it mean vfork parent will be killed. This is definitely incorrect. another process have another oom_adj. we shouldn't ignore their oom_adj (it might have OOM_DISABLE). following caller hit the minefield. =============================== switch (constraint) { case CONSTRAINT_MEMORY_POLICY: oom_kill_process(current, gfp_mask, order, 0, NULL, "No available memory (MPOL_BIND)"); break; Note: force_sig(SIGKILL) send SIGKILL to all thread in the process. We don't need to care multi thread in here. Signed-off-by: KOSAKI Motohiro Cc: Paul Menage Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 17 +---------------- 1 file changed, 1 insertion(+), 16 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 372692294844..ea2147dabba6 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -373,11 +373,6 @@ static void __oom_kill_task(struct task_struct *p, int verbose) static int oom_kill_task(struct task_struct *p) { - struct mm_struct *mm; - struct task_struct *g, *q; - - mm = p->mm; - /* WARNING: mm may not be dereferenced since we did not obtain its * value from get_task_mm(p). This is OK since all we need to do is * compare mm to q->mm below. @@ -386,21 +381,11 @@ static int oom_kill_task(struct task_struct *p) * change to NULL at any time since we do not hold task_lock(p). * However, this is of no concern to us. */ - if (!mm || p->signal->oom_adj == OOM_DISABLE) + if (!p->mm || p->signal->oom_adj == OOM_DISABLE) return 1; __oom_kill_task(p, 1); - /* - * kill all processes that share the ->mm (i.e. all threads), - * but are in a different thread group. Don't let them have access - * to memory reserves though, otherwise we might deplete all memory. - */ - do_each_thread(g, q) { - if (q->mm == mm && !same_thread_group(q, p)) - force_sig(SIGKILL, q); - } while_each_thread(g, q); - return 0; }