From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 2E5326B003D for ; Fri, 13 Mar 2009 01:27:05 -0400 (EDT) Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by e28smtp05.in.ibm.com (8.13.1/8.13.1) with ESMTP id n2D5Qxnt025037 for ; Fri, 13 Mar 2009 10:56:59 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n2D5R7YG1626362 for ; Fri, 13 Mar 2009 10:57:07 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.13.1/8.13.3) with ESMTP id n2D5QwGf010712 for ; Fri, 13 Mar 2009 16:26:58 +1100 Date: Fri, 13 Mar 2009 10:56:53 +0530 From: Balbir Singh Subject: Re: [PATCH 4/4] Memory controller soft limit reclaim on contention (v5) Message-ID: <20090313052653.GG16897@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20090313041341.GA16897@balbir.in.ibm.com> <20090313132426.AF4D.A69D9226@jp.fujitsu.com> <20090313134548.AF50.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090313134548.AF50.A69D9226@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: linux-mm@kvack.org, YAMAMOTO Takashi , lizf@cn.fujitsu.com, Rik van Riel , Andrew Morton , KAMEZAWA Hiroyuki List-ID: * KOSAKI Motohiro [2009-03-13 13:50:26]: > > > > I have two objection to this. > > > > > > > > - "if (!order || !did_some_progress)" mean no call try_to_free_pages() > > > > in order>0 and did_some_progress>0 case. > > > > but mem_cgroup_soft_limit_reclaim() don't have lumpy reclaim. > > > > then, it break high order reclaim. > > > > > > I am sending a fix for this right away. Thanks, the check should be > > > if (order || !did_some_progress) > > > > No. > > > > it isn't enough. > > after is does, order-1 allocation case twrice reclaim (soft limit shrinking > > and normal try_to_free_pages()). > > then, order-1 reclaim makes slower about 2 times. > > > > unfortunately, order-1 allocation is very frequent. it is used for > > kernel stack. > > in normal order-1 reclaim is: > > 1. try_to_free_pages() > 2. get_page_from_freelist() > 3. retry if order-1 page don't exist > > Coundn't you use the same logic? Sorry, forgot to answer this question earlier. I assume that by order-1 you mean 2 pages (2^1). Are you suggesting that if soft limit reclaim fails, we retry? Not sure if I understand your suggestion completely. -- 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