From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [Lsf] IO less throttling and cgroup aware writeback (Was: Re: Preliminary Agenda and Activities for LSF) Date: Tue, 19 Apr 2011 22:26:40 +0800 Message-ID: <20110419142640.GB26482@localhost> References: <20110331222756.GC2904@dastard> <20110401171838.GD20986@redhat.com> <20110401214947.GE6957@dastard> <20110405131359.GA14239@redhat.com> <20110405225639.GB31057@dastard> <20110406153715.GA18777@redhat.com> <20110406160805.GC18777@redhat.com> <20110406171017.GA28689@quack.suse.cz> <20110408015841.GV31057@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Kara , Vivek Goyal , James Bottomley , lsf@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org To: Dave Chinner Return-path: Received: from mga14.intel.com ([143.182.124.37]:40856 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751805Ab1DSO0o (ORCPT ); Tue, 19 Apr 2011 10:26:44 -0400 Content-Disposition: inline In-Reply-To: <20110408015841.GV31057@dastard> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri, Apr 08, 2011 at 11:58:41AM +1000, Dave Chinner wrote: > On Wed, Apr 06, 2011 at 07:10:17PM +0200, Jan Kara wrote: > > On Wed 06-04-11 12:08:05, Vivek Goyal wrote: > > > On Wed, Apr 06, 2011 at 11:37:15AM -0400, Vivek Goyal wrote: > > Well, I wouldn't bother too much with kswapd handling. MM people plan to > > get rid of writeback from direct reclaim and just remove the dirty page > > from LRU and recycle it once flusher thread writes it... > > kswapd is not in the direct reclaim path - it's the background > memory reclaim path. Writeback from direct reclaim is a problem > because of stack usage, and that problem doesn't exist for kswapd. FYI the IO initiated from pageout() in kswapd/direct reclaim can mostly be transfered to the flushers. Here is the early RFC patch, and I'll submit an update soon. http://www.spinics.net/lists/linux-mm/msg09199.html Thanks, Fengguang