From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id C238B6B003D for ; Wed, 11 Feb 2009 06:06:49 -0500 (EST) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n1BB6lUo008660 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Wed, 11 Feb 2009 20:06:47 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 7594945DE55 for ; Wed, 11 Feb 2009 20:06:47 +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 5630C45DD79 for ; Wed, 11 Feb 2009 20:06:47 +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 3AC741DB803A for ; Wed, 11 Feb 2009 20:06:47 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id E0752E18001 for ; Wed, 11 Feb 2009 20:06:46 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH] mm: remove zone->prev_prioriy In-Reply-To: <20090210151247.6747f66e.akpm@linux-foundation.org> References: <28c262360902100257o6a8e2374v42f1ae906c53bcec@mail.gmail.com> <20090210151247.6747f66e.akpm@linux-foundation.org> Message-Id: <20090211195252.C3BD.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Wed, 11 Feb 2009 20:06:46 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: kosaki.motohiro@jp.fujitsu.com, MinChan Kim , kamezawa.hiroyu@jp.fujitsu.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, riel@redhat.com List-ID: > On Tue, 10 Feb 2009 19:57:01 +0900 > MinChan Kim wrote: > > > As you know, prev_priority is used as a measure of how much stress page reclaim. > > But now we doesn't need it due to split-lru's way. > > > > I think it would be better to remain why prev_priority isn't needed any more > > and how split-lru can replace prev_priority's role in changelog. > > > > In future, it help mm newbies understand change history, I think. > > Yes, I'd be fascinated to see that explanation. > > In http://groups.google.pn/group/linux.kernel/browse_thread/thread/fea9c9a0b43162a1 > it was asserted that we intend to use prev_priority again in the future. > > We discussed this back in November: > http://lkml.indiana.edu/hypermail/linux/kernel/0811.2/index.html#00001 > > And I think that I still think that the VM got worse due to its (new) > failure to track previous state. IIRC, the response to that concern > was quite similar to handwavy waffling. Yes. I still think it's valuable code. I think, In theory, VM sould take parallel reclaim bonus. However, recently, KAMEZAWA-san reported memcg prev_priority code are busted due to hierarchical-memory-reclaim and he dislike maintain unused function. http://marc.info/?l=linux-mm&m=123258289017433&w=2 and, at that time I can't show good example workload of parallel reclaim bonus effective. Therefore I agreed to drop this and insert it again at re-using time ;-) -- 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