Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753512Ab0LHG46 (ORCPT ); Wed, 8 Dec 2010 01:56:58 -0500 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:32975 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753301Ab0LHG44 (ORCPT ); Wed, 8 Dec 2010 01:56:56 -0500 Date: Wed, 8 Dec 2010 12:26:50 +0530 From: Balbir Singh To: Minchan Kim Cc: KAMEZAWA Hiroyuki , Johannes Weiner , Andrew Morton , Rik van Riel , KOSAKI Motohiro , linux-mm , LKML , Peter Zijlstra , Wu Fengguang , Nick Piggin , Mel Gorman Subject: Re: [PATCH v4 2/7] deactivate invalidated pages Message-ID: <20101208065650.GP3158@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20101207144923.GB2356@cmpxchg.org> <20101207150710.GA26613@barrios-desktop> <20101207151939.GF2356@cmpxchg.org> <20101207152625.GB608@barrios-desktop> <20101207155645.GG2356@cmpxchg.org> <20101208095642.8128ab33.kamezawa.hiroyu@jp.fujitsu.com> <20101208105637.5103de75.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2780 Lines: 88 * MinChan Kim [2010-12-08 11:15:19]: > On Wed, Dec 8, 2010 at 10:56 AM, KAMEZAWA Hiroyuki > wrote: > > On Wed, 8 Dec 2010 10:43:08 +0900 > > Minchan Kim wrote: > > > >> Hi Kame, > >> > > Hi, > > > >> > I wonder ...how about adding "victim" list for "Reclaim" pages ? Then, we don't need > >> > extra LRU rotation. > >> > >> It can make the code clean. > >> As far as I think, victim list does following as. > >> > >> 1. select victim pages by strong hint > >> 2. move the page from LRU to victim > >> 3. reclaimer always peeks victim list before diving into LRU list. > >> 4-1. If the victim pages is used by others or dirty, it can be moved > >> into LRU, again or remain the page in victim list. > >> If the page is remained victim, when do we move it into LRU again if > >> the reclaimer continues to fail the page? > > When sometone touches it. > > > >> We have to put the new rule. > >> 4-2. If the victim pages isn't used by others and clean, we can > >> reclaim the page asap. > >> > >> AFAIK, strong hints are just two(invalidation, readahead max window heuristic). > >> I am not sure it's valuable to add new hierarchy(ie, LRU, victim, > >> unevictable) for cleaning the minor codes. > >> In addition, we have to put the new rule so it would make the LRU code > >> complicated. > >> I remember how unevictable feature merge is hard. > >> > > yes, it was hard. > > > >> But I am not against if we have more usecases. In this case, it's > >> valuable to implement it although it's not easy. > >> > > > > I wonder "victim list" can be used for something like Cleancache, when > > we have very-low-latency backend devices. > > And we may able to have page-cache-limit, which Balbir proposed as. > > Yes, I thought that, too. I think it would be a good feature in embedded system. > > > > > - kvictimed? will move unmappedd page caches to victim list > > This may work like a InactiveClean list which we had before and make > > sizing easy. > > > > Before further discuss, we need customer's confirm. > We know very well it is very hard to merge if anyone doesn't use. > > Balbir, What do think about it? > The idea seems interesting, I am in the process of refreshing my patches for unmapped page cache control. I presume the process of filling the victim list will be similar to what I have or unmapped page cache isolation. > > > Thanks, > > -Kame > > > > > > > > > > > > -- > Kind regards, > Minchan Kim -- Three Cheers, Balbir -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/