From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id CE3A26B004A for ; Mon, 29 Nov 2010 20:10:25 -0500 (EST) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id oAU1ANvh025768 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 30 Nov 2010 10:10:23 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 1184F45DE4E for ; Tue, 30 Nov 2010 10:10:23 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id ED41845DD74 for ; Tue, 30 Nov 2010 10:10:22 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id E000E1DB803A for ; Tue, 30 Nov 2010 10:10:22 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id AD71C1DB8038 for ; Tue, 30 Nov 2010 10:10:22 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 2/3] Reclaim invalidated page ASAP In-Reply-To: <053e6a3308160a8992af5a47fb4163796d033b08.1291043274.git.minchan.kim@gmail.com> References: <053e6a3308160a8992af5a47fb4163796d033b08.1291043274.git.minchan.kim@gmail.com> Message-Id: <20101130100933.82E9.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 30 Nov 2010 10:10:20 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , linux-mm , LKML , Ben Gamari , Wu Fengguang , Johannes Weiner , Nick Piggin , Mel Gorman List-ID: > invalidate_mapping_pages is very big hint to reclaimer. > It means user doesn't want to use the page any more. > So in order to prevent working set page eviction, this patch > move the page into tail of inactive list by PG_reclaim. > > Please, remember that pages in inactive list are working set > as well as active list. If we don't move pages into inactive list's > tail, pages near by tail of inactive list can be evicted although > we have a big clue about useless pages. It's totally bad. > > Now PG_readahead/PG_reclaim is shared. > fe3cba17 added ClearPageReclaim into clear_page_dirty_for_io for > preventing fast reclaiming readahead marker page. > > In this series, PG_reclaim is used by invalidated page, too. > If VM find the page is invalidated and it's dirty, it sets PG_reclaim > to reclaim asap. Then, when the dirty page will be writeback, > clear_page_dirty_for_io will clear PG_reclaim unconditionally. > It disturbs this serie's goal. > > I think it's okay to clear PG_readahead when the page is dirty, not > writeback time. So this patch moves ClearPageReadahead. > > Signed-off-by: Minchan Kim > Acked-by: Rik van Riel > Cc: Wu Fengguang > Cc: KOSAKI Motohiro > Cc: Johannes Weiner > Cc: Nick Piggin > Cc: Mel Gorman I still dislike this one. I doubt this trick makes much benefit in real world workload. -- 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