Date: Wed, 3 Feb 2010 22:31:27 +0530
From: Balbir Singh <balbir@linux.vnet.ibm.com>
To: Rik van Riel <riel@redhat.com>
Cc: Lubos Lunak <l.lunak@suse.cz>, linux-mm@kvack.org,
       linux-kernel@vger.kernel.org, Andrew Morton <akpm@linux-foundation.org>,
       David Rientjes <rientjes@google.com>,
       KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       Nick Piggin <npiggin@suse.de>, Jiri Kosina <jkosina@suse.cz>
Subject: Re: Improving OOM killer
Message-ID: <20100203170127.GH19641@balbir.in.ibm.com>
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References: <201002012302.37380.l.lunak@suse.cz>
 <4B698CEE.5020806@redhat.com>
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* Rik van Riel <riel@redhat.com> [2010-02-03 09:49:18]:

> On 02/01/2010 05:02 PM, Lubos Lunak wrote:
> 
> >  In other words, use VmRSS for measuring memory usage instead of VmSize, and
> >remove child accumulating.
> 
> I agree with removing the child accumulating code.  That code can
> do a lot of harm with databases like postgresql, or cause the
> system's main service (eg. httpd) to be killed when a broken cgi
> script used up too much memory.
>
> IIRC the child accumulating code was introduced to deal with
> malicious code (fork bombs), but it makes things worse for the
> (much more common) situation of a system without malicious
> code simply running out of memory due to being very busy.
>

For fork bombs, we could do a number of children number test and have
a threshold before we consider a process and its children for
badness().

> I have no strong opinion on using RSS vs VmSize.
> 

David commented and feels strongly about RSS and prefers VmSize.

-- 
	Balbir
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