From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 0EB8D6B007E for ; Tue, 16 Feb 2010 19:04:23 -0500 (EST) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o1H04uqx029888 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Wed, 17 Feb 2010 09:04:56 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id D388E45DE50 for ; Wed, 17 Feb 2010 09:04:55 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id B214845DE4D for ; Wed, 17 Feb 2010 09:04:55 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 9BFC1E38001 for ; Wed, 17 Feb 2010 09:04:55 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 507D51DB803E for ; Wed, 17 Feb 2010 09:04:52 +0900 (JST) Date: Wed, 17 Feb 2010 09:01:24 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [patch -mm 4/9 v2] oom: remove compulsory panic_on_oom mode Message-Id: <20100217090124.398769d5.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20100216090005.f362f869.kamezawa.hiroyu@jp.fujitsu.com> <20100216092311.86bceb0c.kamezawa.hiroyu@jp.fujitsu.com> <20100217084239.265c65ea.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: David Rientjes Cc: Andrew Morton , Rik van Riel , Nick Piggin , Andrea Arcangeli , Balbir Singh , Lubos Lunak , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Tue, 16 Feb 2010 15:54:50 -0800 (PST) David Rientjes wrote: > On Wed, 17 Feb 2010, KAMEZAWA Hiroyuki wrote: > > Then, please leave panic_on_oom=always. > > Even with mempolicy or cpuset 's OOM, we need panic_on_oom=always option. > > And yes, I'll add something similar to memcg. freeze_at_oom or something. > > > > Memcg isn't a special case here, it should also panic the machine if > panic_on_oom == 2, so if we aren't going to remove this option then I > agree with Nick that we need to panic from mem_cgroup_out_of_memory() as > well. Some users use cpusets, for example, for the same effect of memory > isolation as you use memcg, so panicking in one scenario and not the other > is inconsistent. > Hmm, I have a few reason to add special behavior to memcg rather than panic. - freeze_at_oom is enough. If OOM can be notified, the management daemon can do useful jobs. Shutdown all other cgroups or migrate them to other host and do kdump. - memcg's oom is not very complicated. Because we just counts RSS+FileCache But, Hmm...I'd like to go this way. 1. At first, support panic_on_oom=2 in memcg. 2. Second, I'll add OOM-notifier and freeze_at_oom to memcg. and don't call memcg_out_of_memory in oom_kill.c in this case. Because we don't kill anything. Taking coredumps of all procs in memcg is not very difficult. I need to discuss with memcg guys. But this will be a way to go, I think Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org