From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 3EDD26B01C3 for ; Fri, 28 May 2010 02:38:55 -0400 (EDT) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o4S6cqd5008238 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Fri, 28 May 2010 15:38:53 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id B541E45DE4F for ; Fri, 28 May 2010 15:38:52 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 909F345DE51 for ; Fri, 28 May 2010 15:38:52 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 7D7BAE08006 for ; Fri, 28 May 2010 15:38:52 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 3E21EE08003 for ; Fri, 28 May 2010 15:38:52 +0900 (JST) Date: Fri, 28 May 2010 15:34:32 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC] oom-kill: give the dying task a higher priority Message-Id: <20100528153432.a4f5ef2c.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100528062701.GA3519@balbir.in.ibm.com> References: <20100528035147.GD11364@uudg.org> <20100528043339.GZ3519@balbir.in.ibm.com> <20100528134133.7E24.A69D9226@jp.fujitsu.com> <20100528062701.GA3519@balbir.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: balbir@linux.vnet.ibm.com Cc: KOSAKI Motohiro , "Luis Claudio R. Goncalves" , Oleg Nesterov , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Thomas Gleixner , Peter Zijlstra , David Rientjes , Mel Gorman , williams@redhat.com List-ID: On Fri, 28 May 2010 11:57:01 +0530 Balbir Singh wrote: > I am still not convinced, specially if we are running under mem > cgroup. Even setting SCHED_FIFO does not help, you could have other > things like cpusets that might restrict the CPUs you can run on, or > any other policy and we could end up contending anyway with other > SCHED_FIFO tasks. > > > That's the reason I acked it. > > If we could show faster recovery from OOM or anything else, I would be > more convinced. > Off topic. 1. Run a daemon in the highest RT priority. 2. disable OOM for a mem cgroup. 3. The daemon register oom-event-notifier of the mem cgroup. When OOM happens. 4. The daemon receive a event, and then, a) enlarge limit or b) kill a task or c) enlarge limit temporary and kill a task, later, reduce limit again. This is the fastest and promissing operation for memcg users. memcg's oom slowdown happens just because it's limited by a user configuration not by the system. That's a point to be considered. The oom situation can be _immediaterly_ fixed up by enlarge limit as emergency mode. If you has to wait for the end of a task, there will be delay, it's unavoidable. 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