From: Oleg Nesterov <oleg@redhat.com>
To: Sergey Dyasly <dserrg@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.cz>,
linux-mm@kvack.org, David Rientjes <rientjes@google.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Sha Zhengju <handai.szj@taobao.com>
Subject: Re: [PATCH] oom: add pending SIGKILL check for chosen victim
Date: Thu, 25 Apr 2013 18:22:37 +0200 [thread overview]
Message-ID: <20130425162237.GA31671@redhat.com> (raw)
In-Reply-To: <20130425194118.51996d11baa4ed6b18e40e71@gmail.com>
On 04/25, Sergey Dyasly wrote:
>
> But in general case there is still a race,
Yes. Every while_each_thread() in oom-kill is wrong, and I am still not
sure what should/can we do. Will try to think more.
You know, partly this is the known problem. while_each_thread(g,t) is not
safe lockless unless g is the main thread. And another bug is that even
if it is the main thread it can race with exec. The 2nd problem should be
fixed, but when we discussed this previously we were going to disallow
the lockless while_each_thread(sub_thread)...
And yes, I missed these problems when we discussed 6b0c81b3 :/
> Still, I think that fatal_signal_pending() is a sensible check, since the one
> for current task is already there, and there is a patch from David Rientjes
> that does almost the same [1].
Oh, I can't comment this. I leave this to you and David.
Oleg.
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next prev parent reply other threads:[~2013-04-25 16:25 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-22 15:06 [PATCH] oom: add pending SIGKILL check for chosen victim Sergey Dyasly
2013-04-22 19:51 ` Michal Hocko
2013-04-23 15:26 ` dserrg
2013-04-23 15:56 ` Michal Hocko
2013-04-24 14:55 ` Oleg Nesterov
2013-04-24 15:22 ` Michal Hocko
2013-04-24 15:42 ` Oleg Nesterov
2013-04-24 19:33 ` Andrew Morton
2013-04-25 14:49 ` Oleg Nesterov
2013-04-25 15:41 ` Sergey Dyasly
2013-04-25 16:22 ` Oleg Nesterov [this message]
2013-05-02 17:20 ` Oleg Nesterov
2013-05-27 15:49 ` Sergey Dyasly
2013-05-27 16:16 ` Oleg Nesterov
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