From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 88D556B0011 for ; Wed, 27 Apr 2011 22:09:20 -0400 (EDT) Date: Thu, 28 Apr 2011 11:04:00 +0900 From: Daisuke Nishimura Subject: Re: [PATCHv4] memcg: reclaim memory from node in round-robin Message-Id: <20110428110400.2808f50d.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20110428104912.6f86b2ee.kamezawa.hiroyu@jp.fujitsu.com> References: <20110427165120.a60c6609.kamezawa.hiroyu@jp.fujitsu.com> <20110428093513.5a6970c0.kamezawa.hiroyu@jp.fujitsu.com> <20110428103705.a284df87.nishimura@mxp.nes.nec.co.jp> <20110428104912.6f86b2ee.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura , Ying Han , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "balbir@linux.vnet.ibm.com" On Thu, 28 Apr 2011 10:49:12 +0900 KAMEZAWA Hiroyuki wrote: > On Thu, 28 Apr 2011 10:37:05 +0900 > Daisuke Nishimura wrote: > > > + if (time_after(mem->next_scan_node_update, jiffies)) > > > + return; > > > + > > Shouldn't it be time_before() or time_after(jiffies, next_scan_node_update) ? > > > > Looks good to me, otherwise. > > > > time_after(a, b) returns true when a is after b.....you're right. > == > Now, memory cgroup's direct reclaim frees memory from the current node. > But this has some troubles. In usual, when a set of threads works in > cooperative way, they are tend to on the same node. So, if they hit > limits under memcg, it will reclaim memory from themselves, it may be > active working set. > > For example, assume 2 node system which has Node 0 and Node 1 > and a memcg which has 1G limit. After some work, file cacne remains and > and usages are > Node 0: 1M > Node 1: 998M. > > and run an application on Node 0, it will eats its foot before freeing > unnecessary file caches. > > This patch adds round-robin for NUMA and adds equal pressure to each > node. When using cpuset's spread memory feature, this will work very well. > > But yes, better algorithm is appreciated. > > From: Ying Han > Signed-off-by: Ying Han > Signed-off-by: KAMEZAWA Hiroyuki > Acked-by: Daisuke Nishimura -- 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