From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id A54A66B018D for ; Mon, 1 Nov 2010 11:08:44 -0400 (EDT) Date: Mon, 1 Nov 2010 16:08:29 +0100 From: Jan Kara Subject: Re: [PATCH 2/4] writeback: quit background/periodic work when other works are enqueued Message-ID: <20101101150829.GC15406@quack.suse.cz> References: <20100913123110.372291929@intel.com> <20100913130149.994322762@intel.com> <20100914124033.GA4874@quack.suse.cz> <20101101120733.GA9006@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101101120733.GA9006@localhost> Sender: owner-linux-mm@kvack.org To: Wu Fengguang Cc: Jan Kara , "linux-mm@kvack.org" , Mel Gorman , Rik van Riel , Johannes Weiner , Minchan Kim , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Andrew Morton List-ID: On Mon 01-11-10 20:07:33, Wu Fengguang wrote: > On Tue, Sep 14, 2010 at 08:40:33PM +0800, Jan Kara wrote: > > Background writeback are easily livelockable (from a definition of their > > target). This is inconvenient because it can make sync(1) stall forever waiting > > on its queued work to be finished. Generally, when a flusher thread has > > some work queued, someone submitted the work to achieve a goal more specific > > than what background writeback does. So it makes sense to give it a priority > > over a generic page cleaning. > > > > Thus we interrupt background writeback if there is some other work to do. We > > return to the background writeback after completing all the queued work. > > > > Could you please update it? Thanks. > > Honza > > > > PS: I've also attached the full patch if that's more convenient for you. > > You patches are more complete than mine, so let's use them. However I > do prefer to have a standalone wb_check_background_flush() that is > called _after_ wb_check_old_data_flush(). This helps make the writeout > a bit more ordered and the separation itself looks a bit more clean to > me. > > Followed are the slightly updated patches. IMHO they are straightforward > fixes that could be merged before other writeback changes. Yes, the updated patch looks OK to me. Thanks for picking the patches up. Honza -- Jan Kara SUSE Labs, CR -- 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 policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org