Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757114Ab0BDWO7 (ORCPT ); Thu, 4 Feb 2010 17:14:59 -0500 Received: from smtp-out.google.com ([216.239.33.17]:51635 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755091Ab0BDWO5 (ORCPT ); Thu, 4 Feb 2010 17:14:57 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id: references:user-agent:mime-version:content-type:x-system-of-record; b=XrmTtOnmXCLJYf3dfulCG2wI3LdNVEoHqCDcw9mDF3APxuWDm8d77L/u+K9wJVOO9 y2dhGvKwEFJJfgIsj8xbA== Date: Thu, 4 Feb 2010 14:14:50 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Rik van Riel cc: Lubos Lunak , Balbir Singh , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , KOSAKI Motohiro , Nick Piggin , Jiri Kosina Subject: Re: Improving OOM killer In-Reply-To: <4B6B4500.3010603@redhat.com> Message-ID: References: <201002012302.37380.l.lunak@suse.cz> <20100203170127.GH19641@balbir.in.ibm.com> <201002032355.01260.l.lunak@suse.cz> <4B6A1241.60009@redhat.com> <4B6B4500.3010603@redhat.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1296 Lines: 29 On Thu, 4 Feb 2010, Rik van Riel wrote: > > Keep in mind that we're in the oom killer here, though. So we're out of > > memory and we need to kill something; should Apache, Oracle, and postgres > > not be penalized for their cost of running by factoring in something like > > this? > > No, they should not. > > The goal of the OOM killer is to kill some process, so the > system can continue running and automatically become available > again for whatever workload the system was running. > > Killing the parent process of one of the system daemons does > not achieve that goal, because you now caused a service to no > longer be available. > The system daemon wouldn't be killed, though. You're right that this heuristic would prefer the system daemon slightly more as a result of the forkbomb penalty, but the oom killer always attempts to sacrifice a child with a seperate mm before killing the selected task. Since the forkbomb heuristic only adds up those children with seperate mms, we're guaranteed to not kill the daemon itself. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/