Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750715AbVKJJR5 (ORCPT ); Thu, 10 Nov 2005 04:17:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750717AbVKJJR5 (ORCPT ); Thu, 10 Nov 2005 04:17:57 -0500 Received: from smtp.nedstat.nl ([194.109.98.184]:19141 "HELO smtp.nedstat.nl") by vger.kernel.org with SMTP id S1750715AbVKJJR4 (ORCPT ); Thu, 10 Nov 2005 04:17:56 -0500 X-Greylist: Passed host: 194.109.98.185 whitelisted X-Greylist: Passed host: 194.109.98.185 whitelisted X-Greylist: Passed host: 194.109.98.185 whitelisted X-Greylist: Passed host: 194.109.98.185 whitelisted X-Greylist: Passed host: 194.109.98.185 whitelisted Subject: Re: [PATCH 01/16] mm: delayed page activation From: Peter Zijlstra To: Wu Fengguang Cc: Nick Piggin , riel@redhat.com, linux-kernel@vger.kernel.org, Andrew Morton In-Reply-To: <20051109141432.393114000@localhost.localdomain> References: <20051109134938.757187000@localhost.localdomain> <20051109141432.393114000@localhost.localdomain> Content-Type: text/plain Date: Thu, 10 Nov 2005 10:17:44 +0100 Message-Id: <1131614264.14052.25.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1543 Lines: 38 On Wed, 2005-11-09 at 21:49 +0800, Wu Fengguang wrote: > plain text document attachment (mm-delayed-activation.patch) > When a page is referenced the second time in inactive_list, mark it with > PG_activate instead of moving it into active_list immediately. The actual > moving work is delayed to vmscan time. > > This implies two essential changes: > - keeps the adjecency of pages in lru; > - lifts the page reference counter max from 1 to 3. > > And leads to the following improvements: > - read-ahead for a leading reader will not be disturbed by a following reader; > - enables the thrashing protection logic to save pages for following readers; > - keeping relavant pages together helps improve I/O efficiency; > - and also helps decrease vm fragmantation; > - increased refcnt space might help page replacement algorithms. I'm working on a clockpro implementation that essentialy keeps all resident pages on 1 clock. In this case readahead pages will also not fragment over the active/inactive lists but stay in order. Would that also satisfy your requirements? Code can be found at: http://programming.kicks-ass.net/kernel-patches/clockpro-2/ Note however that this is work in progress and rather unstable, there are some livelock scenarios in there. Kind regards, Peter Zijlstra - 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/