From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 7/8] writeback: sync old inodes first in background writeback Date: Mon, 19 Jul 2010 10:21:45 -0400 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 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 To: Mel Gorman Return-path: Content-Disposition: inline In-Reply-To: <1279545090-19169-8-git-send-email-mel@csn.ul.ie> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org 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, 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