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 2E6F76B004A for ; Wed, 20 Jul 2011 02:03:11 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 2C7723EE0B6 for ; Wed, 20 Jul 2011 15:03:08 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 131C345DE54 for ; Wed, 20 Jul 2011 15:03:08 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id D5E5545DE5B for ; Wed, 20 Jul 2011 15:03:07 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id C8EB11DB8051 for ; Wed, 20 Jul 2011 15:03:07 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.240.81.145]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 8F110E08002 for ; Wed, 20 Jul 2011 15:03:07 +0900 (JST) Date: Wed, 20 Jul 2011 14:55:53 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 2/2] memcg: change memcg_oom_mutex to spinlock Message-Id: <20110720145553.7703dbcb.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, Balbir Singh , Andrew Morton , linux-kernel@vger.kernel.org On Thu, 14 Jul 2011 17:29:51 +0200 Michal Hocko wrote: > memcg_oom_mutex is used to protect memcg OOM path and eventfd interface > for oom_control. None of the critical sections which it protects sleep > (eventfd_signal works from atomic context and the rest are simple linked > list resp. oom_lock atomic operations). > Mutex is also too heavy weight for those code paths because it triggers > a lot of scheduling. It also makes makes convoying effects more visible > when we have a big number of oom killing because we take the lock > mutliple times during mem_cgroup_handle_oom so we have multiple places > where many processes can sleep. > > Signed-off-by: Michal Hocko Acked-by: KAMEZAWA Hiroyuki -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org