Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934641Ab0GSOVr (ORCPT ); Mon, 19 Jul 2010 10:21:47 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:57741 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933836Ab0GSOVp (ORCPT ); Mon, 19 Jul 2010 10:21:45 -0400 Date: Mon, 19 Jul 2010 10:21:45 -0400 From: Christoph Hellwig To: Mel Gorman Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin , Rik van Riel , Johannes Weiner , Christoph Hellwig , Wu Fengguang , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Andrew Morton , Andrea Arcangeli Subject: Re: [PATCH 7/8] writeback: sync old inodes first in background writeback Message-ID: <20100719142145.GD12510@infradead.org> References: <1279545090-19169-1-git-send-email-mel@csn.ul.ie> <1279545090-19169-8-git-send-email-mel@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1279545090-19169-8-git-send-email-mel@csn.ul.ie> User-Agent: Mutt/1.5.20 (2009-08-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1013 Lines: 21 On Mon, Jul 19, 2010 at 02:11:29PM +0100, Mel Gorman wrote: > From: Wu Fengguang > > A background flush work may run for ever. So it's reasonable for it to > mimic the kupdate behavior of syncing old/expired inodes first. > > This behavior also makes sense from the perspective of page reclaim. > File pages are added to the inactive list and promoted if referenced > after one recycling. If not referenced, it's very easy for pages to be > cleaned from reclaim context which is inefficient in terms of IO. If > background flush is cleaning pages, it's best it cleans old pages to > help minimise IO from reclaim. Yes, we absolutely do this. Wu, do you have an improved version of the pending or should we put it in this version for now? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/