Re: can't oom-kill zap the victim's memory?
From: Oleg Nesterov <oleg@redhat.com>
Date: 2015-09-19 15:13:08
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(off-topic) On 09/19, Oleg Nesterov wrote:
quoted hunk ↗ jump to hunk
@@ -570,8 +590,8 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, victim = p; } - /* mm cannot safely be dereferenced after task_unlock(victim) */ mm = victim->mm; + atomic_inc(&mm->mm_count);
Btw, I think we need this change anyway. This is pure theoretical, but otherwise this task can exit and free its mm_struct right after task_unlock(), then this mm_struct can be reallocated and used by another task, so we can't trust the "p->mm == mm" check below. Oleg. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>