Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756820Ab0LHCC1 (ORCPT ); Tue, 7 Dec 2010 21:02:27 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:48200 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755519Ab0LHCCX (ORCPT ); Tue, 7 Dec 2010 21:02:23 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Wed, 8 Dec 2010 10:56:37 +0900 From: KAMEZAWA Hiroyuki To: Minchan Kim Cc: 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: <20101208105637.5103de75.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: 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> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.0.3 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1905 Lines: 57 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. - kvictimed? will move unmappedd page caches to victim list This may work like a InactiveClean list which we had before and make sizing easy. Thanks, -Kame -- 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/