From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 2A2FB6B0012 for ; Thu, 28 Apr 2011 06:26:24 -0400 (EDT) Date: Thu, 28 Apr 2011 12:26:06 +0200 From: Johannes Weiner Subject: Re: [RFC 3/8] vmscan: make isolate_lru_page with filter aware Message-ID: <20110428102606.GL12437@cmpxchg.org> References: <232562452317897b5acb1445803410d74233a923.1303833417.git.minchan.kim@gmail.com> <20110427170304.d31c1398.kamezawa.hiroyu@jp.fujitsu.com> <20110428085432.GI12437@cmpxchg.org> <20110428181046.b81635ce.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110428181046.b81635ce.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: Minchan Kim , Andrew Morton , linux-mm , LKML , Christoph Lameter , Johannes Weiner , KOSAKI Motohiro , Mel Gorman , Rik van Riel , Andrea Arcangeli On Thu, Apr 28, 2011 at 06:10:46PM +0900, KAMEZAWA Hiroyuki wrote: > On Thu, 28 Apr 2011 10:54:32 +0200 > Johannes Weiner wrote: > > > On Wed, Apr 27, 2011 at 05:03:04PM +0900, KAMEZAWA Hiroyuki wrote: > > > On Wed, 27 Apr 2011 01:25:20 +0900 > > > Minchan Kim wrote: > > > > > > > In some __zone_reclaim case, we don't want to shrink mapped page. > > > > Nonetheless, we have isolated mapped page and re-add it into > > > > LRU's head. It's unnecessary CPU overhead and makes LRU churning. > > > > > > > > Of course, when we isolate the page, the page might be mapped but > > > > when we try to migrate the page, the page would be not mapped. > > > > So it could be migrated. But race is rare and although it happens, > > > > it's no big deal. > > > > > > > > Cc: Christoph Lameter > > > > Cc: KOSAKI Motohiro > > > > Cc: Mel Gorman > > > > Cc: Rik van Riel > > > > Cc: Andrea Arcangeli > > > > Signed-off-by: Minchan Kim > > > > > > > > > Hmm, it seems mm/memcontrol.c::mem_cgroup_isolate_pages() should be updated, too. > > > > memcg reclaim always does sc->may_unmap = 1. What is there to > > communicate to mem_cgroup_isolate_pages? > > > > Hmm, maybe you're right and nothing to do until memcg need to support soft > limit in zone reclaim mode. I hope no more users. Ah, okay. I thought I may have missed something. Thanks for the clarification, Kame. Acked-by: Johannes Weiner -- 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