From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: David Rientjes <rientjes@google.com>
Cc: kosaki.motohiro@jp.fujitsu.com, Oleg Nesterov <oleg@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Nick Piggin <npiggin@suse.de>
Subject: Re: [PATCH] oom: remove PF_EXITING check completely
Date: Thu, 3 Jun 2010 13:48:09 +0900 (JST) [thread overview]
Message-ID: <20100603120814.7242.A69D9226@jp.fujitsu.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1006021359430.32666@chino.kir.corp.google.com>
> On Wed, 2 Jun 2010, Oleg Nesterov wrote:
>
> > > Today, I've thought to make some bandaid patches for this issue. but
> > > yes, I've reached the same conclusion.
> > >
> > > If we think multithread and core dump situation, all fixes are just
> > > bandaid. We can't remove deadlock chance completely.
> > >
> > > The deadlock is certenaly worst result, then, minor PF_EXITING optimization
> > > doesn't have so much worth.
> >
> > Agreed! I was always wondering if it really helps in practice.
> >
>
> Nack, this certainly does help in practice, it prevents needlessly killing
> additional tasks when one is exiting and may free memory. It's much
> better to defer killing something temporarily if an eligible task (i.e.
> one that has a high probability of memory allocations on current's nodes
> or contributing to its memcg) is exiting.
>
> We depend on this check specifically for our use of cpusets, so please
> don't remove it.
Your claim violate our development process. Oleg pointed this check
doesn't only work well, but also can makes deadlock. So, We certinally
need anything fix. then, I'll remove this check completely at 2.6.35
timeframe.
But this doesn't mean we refuse you make better patch at all. I expect
we can merge very soon if you make such patch.
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next prev parent reply other threads:[~2010-06-03 4:48 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-31 9:33 [PATCH 1/5] oom: select_bad_process: check PF_KTHREAD instead of !mm to skip kthreads KOSAKI Motohiro
2010-05-31 9:35 ` [PATCH 2/5] oom: select_bad_process: PF_EXITING check should take ->mm into account KOSAKI Motohiro
2010-05-31 16:43 ` Oleg Nesterov
2010-06-01 1:10 ` KOSAKI Motohiro
2010-06-01 20:18 ` Oleg Nesterov
2010-06-02 13:54 ` [PATCH] oom: remove PF_EXITING check completely KOSAKI Motohiro
2010-06-02 15:54 ` Oleg Nesterov
2010-06-02 21:02 ` David Rientjes
2010-06-03 4:48 ` KOSAKI Motohiro [this message]
2010-06-03 6:29 ` David Rientjes
2010-06-02 13:54 ` [PATCH] oom: Make coredump interruptible KOSAKI Motohiro
2010-06-02 15:42 ` Oleg Nesterov
2010-06-02 17:29 ` Roland McGrath
2010-06-02 17:53 ` Oleg Nesterov
2010-06-02 18:58 ` Roland McGrath
2010-06-02 20:38 ` Oleg Nesterov
2010-06-03 14:03 ` Oleg Nesterov
2010-06-04 10:54 ` KOSAKI Motohiro
2010-06-04 11:27 ` Oleg Nesterov
2010-06-04 11:34 ` Oleg Nesterov
2010-06-09 19:53 ` Oleg Nesterov
2010-06-09 20:41 ` David Rientjes
2010-06-09 21:03 ` Oleg Nesterov
2010-06-13 11:24 ` KOSAKI Motohiro
2010-06-13 15:53 ` Oleg Nesterov
2010-06-13 17:13 ` uninterruptible CLONE_VFORK (Was: oom: Make coredump interruptible) Oleg Nesterov
2010-06-14 0:56 ` Roland McGrath
2010-06-14 16:33 ` Oleg Nesterov
2010-06-14 19:17 ` Roland McGrath
2010-06-28 17:33 ` Oleg Nesterov
2010-06-28 18:04 ` Roland McGrath
2010-06-14 0:36 ` [PATCH] oom: Make coredump interruptible Roland McGrath
2010-06-14 0:26 ` Roland McGrath
2010-06-01 20:39 ` [PATCH 2/5] oom: select_bad_process: PF_EXITING check should take ->mm into account David Rientjes
2010-05-31 9:36 ` [PATCH 3/5] oom: introduce find_lock_task_mm() to fix !mm false positives KOSAKI Motohiro
2010-06-01 0:57 ` KAMEZAWA Hiroyuki
2010-06-01 20:42 ` David Rientjes
2010-06-02 16:05 ` Minchan Kim
2010-05-31 9:37 ` [PATCH 4/5] oom: the points calculation of child processes must use find_lock_task_mm() too KOSAKI Motohiro
2010-05-31 16:56 ` Oleg Nesterov
2010-05-31 23:48 ` KOSAKI Motohiro
2010-05-31 9:38 ` [PATCH 5/5] oom: __oom_kill_task() " KOSAKI Motohiro
2010-06-01 1:02 ` KAMEZAWA Hiroyuki
2010-06-01 20:44 ` David Rientjes
2010-06-01 0:54 ` [PATCH 1/5] oom: select_bad_process: check PF_KTHREAD instead of !mm to skip kthreads KAMEZAWA Hiroyuki
2010-06-01 20:36 ` David Rientjes
2010-06-01 21:20 ` Oleg Nesterov
2010-06-01 21:26 ` David Rientjes
2010-06-02 13:54 ` KOSAKI Motohiro
2010-06-02 21:09 ` David Rientjes
2010-06-02 21:33 ` Oleg Nesterov
2010-06-02 21:46 ` David Rientjes
2010-06-03 14:27 ` Oleg Nesterov
2010-06-03 20:11 ` David Rientjes
2010-06-02 15:32 ` Minchan Kim
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