From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754540Ab0FPBjy (ORCPT ); Tue, 15 Jun 2010 21:39:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22706 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753286Ab0FPBjw (ORCPT ); Tue, 15 Jun 2010 21:39:52 -0400 Message-ID: <4C182097.2070603@redhat.com> Date: Tue, 15 Jun 2010 20:53:43 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-2.fc12 Lightning/1.0b2pre Thunderbird/3.0.4 MIME-Version: 1.0 To: KAMEZAWA Hiroyuki CC: Mel Gorman , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin , Johannes Weiner , Christoph Hellwig , Andrew Morton Subject: Re: [PATCH 12/12] vmscan: Do not writeback pages in direct reclaim References: <1276514273-27693-1-git-send-email-mel@csn.ul.ie> <1276514273-27693-13-git-send-email-mel@csn.ul.ie> <4C16A567.4080000@redhat.com> <20100615114510.GE26788@csn.ul.ie> <4C17815A.8080402@redhat.com> <20100615135928.GK26788@csn.ul.ie> <4C178868.2010002@redhat.com> <20100615141601.GL26788@csn.ul.ie> <20100616091755.7121c7d3.kamezawa.hiroyu@jp.fujitsu.com> <4C181AFD.5060503@redhat.com> <20100616093958.00673123.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100616093958.00673123.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/15/2010 08:39 PM, KAMEZAWA Hiroyuki wrote: > Hmm, or do you recommend no-dirty-page-writeback when a memcg hits limit ? > Maybe we'll see much swaps. > > I want to go with this for a while, changing memcg's behavior will took > some amounts of time, there are only a few developpers. One thing we can do, for kswapd, memcg and direct reclaim alike, is to tell the flusher threads to flush pages related to a pageout candidate page to disk. That way the reclaiming processes can wait on some disk IO to finish, while the flusher thread takes care of the actual flushing. That should also fix the "kswapd filesystem IO has really poor IO patterns" issue. There's no reason not to fix this issue the right way. -- All rights reversed From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rik van Riel Subject: Re: [PATCH 12/12] vmscan: Do not writeback pages in direct reclaim Date: Tue, 15 Jun 2010 20:53:43 -0400 Message-ID: <4C182097.2070603@redhat.com> References: <1276514273-27693-1-git-send-email-mel@csn.ul.ie> <1276514273-27693-13-git-send-email-mel@csn.ul.ie> <4C16A567.4080000@redhat.com> <20100615114510.GE26788@csn.ul.ie> <4C17815A.8080402@redhat.com> <20100615135928.GK26788@csn.ul.ie> <4C178868.2010002@redhat.com> <20100615141601.GL26788@csn.ul.ie> <20100616091755.7121c7d3.kamezawa.hiroyu@jp.fujitsu.com> <4C181AFD.5060503@redhat.com> <20100616093958.00673123.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Mel Gorman , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin , Johannes Weiner , Christoph Hellwig , Andrew Morton To: KAMEZAWA Hiroyuki Return-path: In-Reply-To: <20100616093958.00673123.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On 06/15/2010 08:39 PM, KAMEZAWA Hiroyuki wrote: > Hmm, or do you recommend no-dirty-page-writeback when a memcg hits limit ? > Maybe we'll see much swaps. > > I want to go with this for a while, changing memcg's behavior will took > some amounts of time, there are only a few developpers. One thing we can do, for kswapd, memcg and direct reclaim alike, is to tell the flusher threads to flush pages related to a pageout candidate page to disk. That way the reclaiming processes can wait on some disk IO to finish, while the flusher thread takes care of the actual flushing. That should also fix the "kswapd filesystem IO has really poor IO patterns" issue. There's no reason not to fix this issue the right way. -- All rights reversed -- 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