From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 1A4686B007B for ; Tue, 16 Feb 2010 18:54:28 -0500 (EST) Received: from spaceape24.eur.corp.google.com (spaceape24.eur.corp.google.com [172.28.16.76]) by smtp-out.google.com with ESMTP id o1GNstIi001437 for ; Tue, 16 Feb 2010 23:54:55 GMT Received: from pzk9 (pzk9.prod.google.com [10.243.19.137]) by spaceape24.eur.corp.google.com with ESMTP id o1GNrARE003212 for ; Tue, 16 Feb 2010 15:54:54 -0800 Received: by pzk9 with SMTP id 9so5023970pzk.28 for ; Tue, 16 Feb 2010 15:54:53 -0800 (PST) Date: Tue, 16 Feb 2010 15:54:50 -0800 (PST) From: David Rientjes Subject: Re: [patch -mm 4/9 v2] oom: remove compulsory panic_on_oom mode In-Reply-To: <20100217084239.265c65ea.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: 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 Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki 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 Wed, 17 Feb 2010, KAMEZAWA Hiroyuki wrote: > Please don't. I had a chance to talk with customer support team and talked > about panic_on_oom briefly. I understood that panic_on_oom_alyways+kdump > is the strongest tool for investigating customer's OOM situtation and do > the best advice to them. panic_on_oom_always+kdump is the 100% information > as snapshot when oom-killer happens. Then, it's easy to investigate and > explain what is wront. They sometimes discover memory leak (by some prorietary > driver) or miss-configuration of the system (as using unnecessary bounce buffer.) > Ok, I'm not looking to cause your customers unnecessary grief by removing an option that they use, even though the same effect is possible by setting all tasks to OOM_DISABLE. I'll remove this patch in the next revision. > 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. -- 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