From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id EF8CB6B0044 for ; Mon, 14 Dec 2009 23:54:46 -0500 (EST) Received: from kpbe17.cbf.corp.google.com (kpbe17.cbf.corp.google.com [172.25.105.81]) by smtp-out.google.com with ESMTP id nBF4sinV025405 for ; Mon, 14 Dec 2009 20:54:44 -0800 Received: from pzk7 (pzk7.prod.google.com [10.243.19.135]) by kpbe17.cbf.corp.google.com with ESMTP id nBF4seWI021718 for ; Mon, 14 Dec 2009 20:54:41 -0800 Received: by pzk7 with SMTP id 7so7137634pzk.30 for ; Mon, 14 Dec 2009 20:54:40 -0800 (PST) Date: Mon, 14 Dec 2009 20:54:37 -0800 (PST) From: David Rientjes Subject: Re: [BUGFIX][PATCH] oom-kill: fix NUMA consraint check with nodemask v4.2 In-Reply-To: <20091215133546.6872fc4f.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: References: <20091110162121.361B.A69D9226@jp.fujitsu.com> <20091110171704.3800f081.kamezawa.hiroyu@jp.fujitsu.com> <20091111112404.0026e601.kamezawa.hiroyu@jp.fujitsu.com> <20091111134514.4edd3011.kamezawa.hiroyu@jp.fujitsu.com> <20091111142811.eb16f062.kamezawa.hiroyu@jp.fujitsu.com> <20091111152004.3d585cee.kamezawa.hiroyu@jp.fujitsu.com> <20091111153414.3c263842.kamezawa.hiroyu@jp.fujitsu.com> <20091118095824.076c211f.kamezawa.hiroyu@jp.fujitsu.com> <20091214171632.0b34d833.akpm@linux-foundation.org> <20091215103202.eacfd64e.kamezawa.hiroyu@jp.fujitsu.com> <20091215133546.6872fc4f.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 , Daisuke Nishimura , KOSAKI Motohiro , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter List-ID: On Tue, 15 Dec 2009, KAMEZAWA Hiroyuki wrote: > > I would agree only if the oom killer used total_vm as a the default, it is > > long-standing and allows for the aforementioned capability that you lose > > with rss. I have no problem with the added sysctl to use rss as the > > baseline when enabled. > > > I'll prepare a patch for adds > > sysctl_oom_kill_based_on_rss (default=0) > > ok ? > I have no strong feelings either for or against that, I guess users who want to always kill the biggest memory hogger even when single page __GFP_WAIT allocations fail could use it. I'm not sure it would get much use, though. I think we should methodically work out an oom killer badness rewrite that won't compound the problem by adding more and more userspace knobs. In other words, we should slow down, construct a list of goals that we want to achieve, and then see what type of solution we can create. A few requirements that I have: - we must be able to define when a task is a memory hogger; this is currently done by /proc/pid/oom_adj relying on the overall total_vm size of the task as a baseline. Most users should have a good sense of when their task is using more memory than expected and killing a memory leaker should always be the optimal oom killer result. A better set of units other than a shift on total_vm would be helpful, though. - we must prefer tasks that run on a cpuset or mempolicy's nodes if the oom condition is constrained by that cpuset or mempolicy and its not a system-wide issue. - we must be able to polarize the badness heuristic to always select a particular task is if its very low priority or disable oom killing for a task if its must-run. The proposal may be to remove /proc/pid/oom_adj completely since I know both you and KOSAKI-san dislike it, but we'd need an alternative which keeps the above functionality intact. -- 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