Messages in this thread | | | Date | Thu, 28 Nov 2013 19:37:02 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH] Fix race between oom kill and task exit |
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On 11/28, Ma, Xindong wrote: > > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -412,16 +412,6 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, > static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL, > DEFAULT_RATELIMIT_BURST); > > - /* > - * If the task is already exiting, don't alarm the sysadmin or kill > - * its children or threads, just set TIF_MEMDIE so it can die quickly > - */ > - if (p->flags & PF_EXITING) { > - set_tsk_thread_flag(p, TIF_MEMDIE); > - put_task_struct(p); > - return; > - } > - > if (__ratelimit(&oom_rs)) > dump_header(p, gfp_mask, order, memcg, nodemask); > > @@ -437,6 +427,16 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, > * still freeing memory. > */ > read_lock(&tasklist_lock); > + /* > + * If the task is already exiting, don't alarm the sysadmin or kill > + * its children or threads, just set TIF_MEMDIE so it can die quickly > + */ > + if (p->flags & PF_EXITING) { > + set_tsk_thread_flag(p, TIF_MEMDIE); > + put_task_struct(p); > + read_unlock(&tasklist_lock); > + return; > + }
I got lost... didn't we recently discussed the similar patch from Sameer?
This one doesn't look right. find_lock_task_mm() after unlock(tasklist) can hit the same problem.
I belive the patch from Sameer was correct.
Oleg.
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