From: Oleg Nesterov <oleg@redhat.com>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Hugh Dickins <hughd@google.com>,
linux-mm@kvack.org, Andrey Vagin <avagin@openvz.org>
Subject: Re: [patch] oom: prevent unnecessary oom kills or kernel panics
Date: Sat, 12 Mar 2011 13:34:13 +0100 [thread overview]
Message-ID: <20110312123413.GA18351@redhat.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1103111142260.30699@chino.kir.corp.google.com>
On 03/11, David Rientjes wrote:
>
> On Wed, 9 Mar 2011, Andrew Morton wrote:
>
> > If Oleg's test program cause a hang with
> > oom-prevent-unnecessary-oom-kills-or-kernel-panics.patch and doesn't
> > cause a hang without
> > oom-prevent-unnecessary-oom-kills-or-kernel-panics.patch then that's a
> > big problem for
> > oom-prevent-unnecessary-oom-kills-or-kernel-panics.patch, no?
> >
>
> It's a problem, but not because of
> oom-prevent-unnecessary-oom-kills-or-kernel-panics.patch.
It is, afaics. oom-killer can't ussume that a single PF_EXITING && p->mm
thread is going to free the memory.
> If we don't
> have this patch, then we have a trivial panic when an oom kill occurs in a
> cpuset with no other eligible processes, the oom killed thread group
> leader exits
It is not clear what "leader exits" actually mean. OK, perhaps you mean
its ->mm == NULL.
> but its other threads do not and they trigger oom kills
> themselves. for_each_process() does not iterate over these threads and so
> it finds no eligible threads to kill and then panics
Could you explain what do you mean? No need to kill these threads, they
are already killed, we should wait until they all exit.
> I'll look at Oleg's test case
> and see what can be done to fix that condition, but the answer isn't to
> ignore eligible threads that can be killed.
Once again, they are already killed. Or I do not understand what you meant.
Could you please explain the problem in more details?
Also. Could you please look at the patches I sent?
[PATCH 1/1] oom_kill_task: mark every thread as TIF_MEMDIE
[PATCH v2 1/1] select_bad_process: improve the PF_EXITING check
Note also the note about "p == current" check. it should be fixed too.
Oleg.
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next prev parent reply other threads:[~2011-03-12 12:43 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-01 19:09 [patch] oom: prevent unnecessary oom kills or kernel panics David Rientjes
2011-03-03 1:20 ` KOSAKI Motohiro
2011-03-03 19:53 ` David Rientjes
2011-03-06 11:14 ` KOSAKI Motohiro
2011-03-06 22:06 ` David Rientjes
2011-03-08 0:24 ` KOSAKI Motohiro
2011-03-08 2:01 ` KOSAKI Motohiro
2011-03-08 13:42 ` Oleg Nesterov
2011-03-08 23:57 ` David Rientjes
2011-03-09 10:36 ` KOSAKI Motohiro
2011-03-09 11:06 ` Oleg Nesterov
2011-03-09 20:32 ` David Rientjes
2011-03-10 12:05 ` Oleg Nesterov
2011-03-10 15:40 ` [PATCH 0/1] Was: " Oleg Nesterov
2011-03-10 15:41 ` [PATCH 1/1] oom_kill_task: mark every thread as TIF_MEMDIE Oleg Nesterov
2011-03-13 1:08 ` David Rientjes
2011-03-10 16:36 ` [PATCH 0/1] select_bad_process: improve the PF_EXITING check Oleg Nesterov
2011-03-10 16:37 ` [PATCH 1/1] " Oleg Nesterov
2011-03-10 16:40 ` [PATCH 0/1] " Oleg Nesterov
2011-03-10 17:18 ` [PATCH v2 " Oleg Nesterov
2011-03-10 17:19 ` [PATCH v2 1/1] " Oleg Nesterov
2011-03-13 1:06 ` [patch] oom: prevent unnecessary oom kills or kernel panics David Rientjes
2011-03-09 23:19 ` Andrew Morton
2011-03-11 19:45 ` David Rientjes
2011-03-12 12:34 ` Oleg Nesterov [this message]
2011-03-12 13:43 ` [PATCH 0/3] oom: TIF_MEMDIE/PF_EXITING fixes Oleg Nesterov
2011-03-12 13:44 ` [PATCH 1/3] oom: oom_kill_task: mark every thread as TIF_MEMDIE Oleg Nesterov
2011-03-13 1:14 ` David Rientjes
2011-03-12 13:44 ` [PATCH 2/3] oom: select_bad_process: improve the PF_EXITING check Oleg Nesterov
2011-03-12 13:44 ` [PATCH 3/3] oom: select_bad_process: use same_thread_group() Oleg Nesterov
2011-03-12 19:40 ` [PATCH 0/3] oom: TIF_MEMDIE/PF_EXITING fixes Hugh Dickins
2011-03-13 8:53 ` KOSAKI Motohiro
2011-03-13 21:27 ` Oleg Nesterov
2011-03-14 19:04 ` [PATCH 0/3 for 2.6.38] oom: fixes Oleg Nesterov
2011-03-14 19:04 ` [PATCH 1/3 for 2.6.38] oom: oom_kill_process: don't set TIF_MEMDIE if !p->mm Oleg Nesterov
2011-03-14 19:35 ` Linus Torvalds
2011-03-14 20:31 ` Oleg Nesterov
2011-03-14 20:32 ` David Rientjes
2011-03-15 19:12 ` Oleg Nesterov
2011-03-15 19:51 ` David Rientjes
2011-03-14 20:22 ` David Rientjes
2011-03-15 18:53 ` Oleg Nesterov
2011-03-15 19:54 ` David Rientjes
2011-03-15 21:16 ` Oleg Nesterov
2011-03-14 19:05 ` [PATCH 2/3 for 2.6.38] oom: select_bad_process: ignore TIF_MEMDIE zombies Oleg Nesterov
2011-03-14 20:50 ` David Rientjes
2011-03-14 19:05 ` [PATCH 3/3 for 2.6.38] oom: oom_kill_process: fix the child_points logic Oleg Nesterov
2011-03-14 20:41 ` David Rientjes
2011-03-15 19:21 ` Oleg Nesterov
2011-03-13 11:36 ` [PATCH 0/3] oom: TIF_MEMDIE/PF_EXITING fixes KOSAKI Motohiro
2011-03-13 1:11 ` [patch] oom: prevent unnecessary oom kills or kernel panics David Rientjes
2011-03-13 1:15 ` [patch -mm] oom: avoid deferring oom killer if exiting task is being traced David Rientjes
2011-03-14 17:40 ` Oleg Nesterov
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