From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id 80D006B0069 for ; Sun, 6 Nov 2011 21:35:25 -0500 (EST) Received: from m2.gw.fujitsu.co.jp (unknown [10.0.50.72]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 5CD8E3EE0C1 for ; Mon, 7 Nov 2011 11:35:22 +0900 (JST) Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 40DA045DE4E for ; Mon, 7 Nov 2011 11:35:22 +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 1BEA845DE6B for ; Mon, 7 Nov 2011 11:35:22 +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 025AF1DB803A for ; Mon, 7 Nov 2011 11:35:22 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.240.81.145]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id BAE9B1DB8044 for ; Mon, 7 Nov 2011 11:35:21 +0900 (JST) Date: Mon, 7 Nov 2011 11:34:17 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [rfc 2/3] mm: vmscan: treat inactive cycling as neutral Message-Id: <20111107113417.1b7581a5.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20111102163213.GI19965@redhat.com> References: <20110808110658.31053.55013.stgit@localhost6> <4E3FD403.6000400@parallels.com> <20111102163056.GG19965@redhat.com> <20111102163213.GI19965@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Konstantin Khlebnikov , Pekka Enberg , "linux-mm@kvack.org" , Andrew Morton , "linux-kernel@vger.kernel.org" , Wu Fengguang , Johannes Weiner , Rik van Riel , Mel Gorman , Minchan Kim , Gene Heskett On Wed, 2 Nov 2011 17:32:13 +0100 Johannes Weiner wrote: > Each page that is scanned but put back to the inactive list is counted > as a successful reclaim, which tips the balance between file and anon > lists more towards the cycling list. > > This does - in my opinion - not make too much sense, but at the same > time it was not much of a problem, as the conditions that lead to an > inactive list cycle were mostly temporary - locked page, concurrent > page table changes, backing device congested - or at least limited to > a single reclaimer that was not allowed to unmap or meddle with IO. > More important than being moderately rare, those conditions should > apply to both anon and mapped file pages equally and balance out in > the end. > > Recently, we started cycling file pages in particular on the inactive > list much more aggressively, for used-once detection of mapped pages, > and when avoiding writeback from direct reclaim. > > Those rotated pages do not exactly speak for the reclaimability of the > list they sit on and we risk putting immense pressure on file list for > no good reason. > > Instead, count each page not reclaimed and put back to any list, > active or inactive, as rotated, so they are neutral with respect to > the scan/rotate ratio of the list class, as they should be. > > Signed-off-by: Johannes Weiner I think this makes sense. Acked-by: KAMEZAWA Hiroyuki I wonder it may be better to have victim list for written-backed pages.. -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org