From: David Rientjes <rientjes@google.com>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: "Luis Claudio R. Goncalves" <lclaudio@uudg.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>, Oleg Nesterov <oleg@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Nick Piggin <npiggin@suse.de>
Subject: Re: [PATCH 09/12] oom: remove PF_EXITING check completely
Date: Wed, 2 Jun 2010 23:34:52 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.00.1006022332320.22441@chino.kir.corp.google.com> (raw)
In-Reply-To: <20100603152436.7262.A69D9226@jp.fujitsu.com>
On Thu, 3 Jun 2010, KOSAKI Motohiro wrote:
> Currently, PF_EXITING check is completely broken. because 1) It only
> care main-thread and ignore sub-threads
Then check the subthreads.
> 2) If user enable core-dump
> feature, it can makes deadlock because the task during coredump ignore
> SIGKILL.
>
It may ignore SIGKILL, but does not ignore fatal_signal_pending() being
true which gives it access to memory reserves with my patchset so that it
may quickly finish.
> The deadlock is certenaly worst result, then, minor PF_EXITING
> optimization worth is relatively ignorable.
>
> This patch removes it.
>
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> Acked-by: Oleg Nesterov <oleg@redhat.com>
Nacked-by: David Rientjes <rientjes@google.com>
You have no real world experience in using the oom killer for memory
containment and don't understand how critical it is to protect other
vital system tasks that are needlessly killed as the result of this patch.
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next prev parent reply other threads:[~2010-06-03 6:35 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-03 5:48 [mmotm 0521][PATCH 0/12] various OOM fixes for 2.6.35 KOSAKI Motohiro
2010-06-03 5:49 ` [PATCH 01/12] oom: select_bad_process: check PF_KTHREAD instead of !mm to skip kthreads KOSAKI Motohiro
2010-06-03 5:50 ` [PATCH 02/12] oom: introduce find_lock_task_mm() to fix !mm false positives KOSAKI Motohiro
2010-06-03 6:12 ` Minchan Kim
2010-06-03 6:52 ` KOSAKI Motohiro
2010-06-03 5:51 ` [PATCH 03/12] oom: the points calculation of child processes must use find_lock_task_mm() too KOSAKI Motohiro
2010-06-03 6:20 ` Minchan Kim
2010-06-03 5:52 ` [PATCH 04/12] oom: __oom_kill_task() " KOSAKI Motohiro
2010-06-03 5:53 ` [PATCH 05/12] oom: make oom_unkillable() helper function KOSAKI Motohiro
2010-06-03 6:11 ` [mmotm 0521][PATCH 0/12] various OOM fixes for 2.6.35 Minchan Kim
2010-06-03 6:23 ` [PATCH 06/12] oom: remove warning for in mm-less task __oom_kill_process() KOSAKI Motohiro
2010-06-03 6:31 ` KAMEZAWA Hiroyuki
2010-06-03 6:37 ` David Rientjes
2010-06-03 6:23 ` [PATCH 07/12] oom: Fix child process iteration properly KOSAKI Motohiro
2010-06-03 6:33 ` KAMEZAWA Hiroyuki
2010-06-03 6:24 ` [PATCH 08/12] oom: dump_tasks() use find_lock_task_mm() too KOSAKI Motohiro
2010-06-03 6:34 ` KAMEZAWA Hiroyuki
2010-06-03 15:21 ` Oleg Nesterov
2010-06-03 15:26 ` Oleg Nesterov
2010-06-03 20:12 ` David Rientjes
2010-06-03 22:01 ` Oleg Nesterov
2010-06-03 23:18 ` David Rientjes
2010-06-04 10:54 ` [PATCH 13/12] oom: dump_header() need tasklist_lock KOSAKI Motohiro
2010-06-03 6:25 ` [PATCH 09/12] oom: remove PF_EXITING check completely KOSAKI Motohiro
2010-06-03 6:34 ` David Rientjes [this message]
2010-06-03 14:00 ` Oleg Nesterov
2010-06-03 20:26 ` David Rientjes
2010-06-03 22:11 ` Oleg Nesterov
2010-06-03 23:23 ` David Rientjes
2010-06-04 10:04 ` Oleg Nesterov
2010-06-04 10:54 ` KOSAKI Motohiro
2010-06-03 6:36 ` KAMEZAWA Hiroyuki
2010-06-03 6:26 ` [PATCH 10/12] oom: sacrifice child with highest badness score for parent KOSAKI Motohiro
2010-06-03 6:26 ` [PATCH 11/12] oom: remove special handling for pagefault ooms KOSAKI Motohiro
2010-06-03 6:27 ` [PATCH 12/12] oom: give current access to memory reserves if it has been killed KOSAKI Motohiro
2010-06-08 11:41 ` KOSAKI Motohiro
2010-06-08 18:26 ` David Rientjes
2010-06-08 11:41 ` [mmotm 0521][PATCH 0/12] various OOM fixes for 2.6.35 KOSAKI Motohiro
2010-06-08 11:41 ` KOSAKI Motohiro
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