Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933657Ab0BPXzB (ORCPT ); Tue, 16 Feb 2010 18:55:01 -0500 Received: from smtp-out.google.com ([216.239.44.51]:57080 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932771Ab0BPXzA (ORCPT ); Tue, 16 Feb 2010 18:55:00 -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=V+jlklQceQAnsnUOGOHUR2ZNMPt4IvkIKh/oZ8dN248TS4EuwFmI1Bmz4BWD/jtXx sr3chprThOquiehtbuXZA== Date: Tue, 16 Feb 2010 15:54:50 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com 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 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> 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: 1646 Lines: 32 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 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/