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 SMTP id 739026B003D for ; Wed, 11 Mar 2009 23:52:52 -0400 (EDT) Received: from mt1.gw.fujitsu.co.jp ([10.0.50.74]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n2C3qnhQ005914 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Thu, 12 Mar 2009 12:52:49 +0900 Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id C4F1645DE4E for ; Thu, 12 Mar 2009 12:52:47 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 63C5145DE50 for ; Thu, 12 Mar 2009 12:52:47 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 818AFE0800D for ; Thu, 12 Mar 2009 12:52:46 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 2ECECE08006 for ; Thu, 12 Mar 2009 12:52:46 +0900 (JST) Date: Thu, 12 Mar 2009 12:51:24 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [BUGFIX][PATCH 1/5] memcg use correct scan number at reclaim Message-Id: <20090312125124.06af6ad9.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090312034918.GB23583@balbir.in.ibm.com> References: <20090312095247.bf338fe8.kamezawa.hiroyu@jp.fujitsu.com> <20090312095516.53a2d029.kamezawa.hiroyu@jp.fujitsu.com> <20090312034918.GB23583@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: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "nishimura@mxp.nes.nec.co.jp" , "kosaki.motohiro@jp.fujitsu.com" , "akpm@linux-foundation.org" List-ID: On Thu, 12 Mar 2009 09:19:18 +0530 Balbir Singh wrote: > * KAMEZAWA Hiroyuki [2009-03-12 09:55:16]: > > > Andrew, this [1/5] is a bug fix, others are not. > > > > == > > From: KOSAKI Motohiro > > > > Even when page reclaim is under mem_cgroup, # of scan page is determined by > > status of global LRU. Fix that. > > > > Signed-off-by: KOSAKI Motohiro > > Signed-off-by: KAMEZAWA Hiroyuki > > --- > > mm/vmscan.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > Index: mmotm-2.6.29-Mar10/mm/vmscan.c > > =================================================================== > > --- mmotm-2.6.29-Mar10.orig/mm/vmscan.c > > +++ mmotm-2.6.29-Mar10/mm/vmscan.c > > @@ -1470,7 +1470,7 @@ static void shrink_zone(int priority, st > > int file = is_file_lru(l); > > int scan; > > > > - scan = zone_page_state(zone, NR_LRU_BASE + l); > > + scan = zone_nr_pages(zone, sc, l); > > I have the exact same patch in my patch queue. BTW, mem_cgroup_zone_nr_pages is > buggy. We don't hold any sort of lock while extracting > MEM_CGROUP_ZSTAT (ideally we need zone->lru_lock). Without that how do > we guarantee that MEM_CGRUP_ZSTAT is not changing at the same time as > we are reading it? > Is it big problem ? We don't need very precise value and ZSTAT just have increment/decrement. So, I tend to ignore this small race. (and it's unsigned long, not long long.) Thanks, -Kame > > if (priority) { > > scan >>= priority; > > scan = (scan * percent[file]) / 100; > > > > > > -- > Balbir > -- 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