Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756585Ab1DLAfW (ORCPT ); Mon, 11 Apr 2011 20:35:22 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:52001 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756467Ab1DLAfU (ORCPT ); Mon, 11 Apr 2011 20:35:20 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Andrew Morton Subject: Re: [PATCH 2/4] remove boost_dying_task_prio() Cc: kosaki.motohiro@jp.fujitsu.com, Andrey Vagin , Minchan Kim , KAMEZAWA Hiroyuki , "Luis Claudio R. Goncalves" , LKML , linux-mm , David Rientjes , Oleg Nesterov , Linus Torvalds In-Reply-To: <20110411145832.ae133cf8.akpm@linux-foundation.org> References: <20110411143215.0074.A69D9226@jp.fujitsu.com> <20110411145832.ae133cf8.akpm@linux-foundation.org> Message-Id: <20110412093503.43EF.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.56.05 [ja] Date: Tue, 12 Apr 2011 09:35:16 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1241 Lines: 32 Hi > On Mon, 11 Apr 2011 14:31:18 +0900 (JST) > KOSAKI Motohiro wrote: > > > This is a almost revert commit 93b43fa (oom: give the dying > > task a higher priority). > > > > The commit dramatically improve oom killer logic when fork-bomb > > occur. But, I've found it has nasty corner case. Now cpu cgroup > > has strange default RT runtime. It's 0! That said, if a process > > under cpu cgroup promote RT scheduling class, the process never > > run at all. > > hm. How did that happen? I thought that sched_setscheduler() modifies > only a single thread, and that thread is in the process of exiting? If admin insert !RT process into a cpu cgroup of setting rtruntime=0, usually it run perfectly because !RT task isn't affected from rtruntime knob, but If it promote RT task, by explicit setscheduler() syscall or OOM, the task can't run at all. In short, now oom killer don't work at all if admin are using cpu cgroup and don't touch rtruntime knob. -- 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/