From: Oleg Nesterov <oleg@redhat.com>
To: David Rientjes <rientjes@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Hugh Dickins <hughd@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Andrey Vagin <avagin@openvz.org>,
Frantisek Hrbata <fhrbata@redhat.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3 for 2.6.38] oom: oom_kill_process: don't set TIF_MEMDIE if !p->mm
Date: Tue, 15 Mar 2011 20:12:56 +0100 [thread overview]
Message-ID: <20110315191256.GB21640@redhat.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1103141322390.31514@chino.kir.corp.google.com>
On 03/14, David Rientjes wrote:
>
> On Mon, 14 Mar 2011, Linus Torvalds wrote:
>
> > The combination of testing PF_EXITING and p->mm just doesn't seem to
> > make any sense.
> >
>
> Right, it doesn't (and I recently removed testing the combination from
> select_bad_process() in -mm). The check for PF_EXITING in the oom killer
> is purely to avoid needlessly killing tasks when something is already
> exiting
Maybe 0/3 wasn't clear enough. This patches does not try to fix things,
it only tries to close the hole in 2.6.38. But it was already released
today.
> and will (hopefully) be freeing its memory soon.
This is not clear to me.
When I did this change I looked at 81236810226f71bd9ff77321c8e8276dae7efc61
and the changelog says:
__oom_kill_task() is called to elevate the task's timeslice and give it
access to memory reserves so that it may quickly exit.
This privilege is unnecessary, however, if the task has already detached
its mm.
Now you are saing this is pointless.
OK. I already said I do not understand this special case. Perhaps I'll ask
the questions later.
> If an eligible
> thread is found to be PF_EXITING,
The problem is, we can't trust per-thread PF_EXITING checks. But I guess
we will discuss this more anyway.
Oleg.
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next prev parent reply other threads:[~2011-03-15 19:21 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
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 [this message]
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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