Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759596AbXEUQBy (ORCPT ); Mon, 21 May 2007 12:01:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756759AbXEUQBp (ORCPT ); Mon, 21 May 2007 12:01:45 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:56810 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755150AbXEUQBo (ORCPT ); Mon, 21 May 2007 12:01:44 -0400 Date: Mon, 21 May 2007 18:00:29 +0200 From: Ingo Molnar To: Con Kolivas Cc: Nick Piggin , Ray Lee , ck list , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] mm: swap prefetch improvements Message-ID: <20070521160029.GA28715@elte.hu> References: <20070430162007.ad46e153.akpm@linux-foundation.org> <200705121446.04191.kernel@kolivas.org> <20070521100320.GA1801@elte.hu> <200705212344.27511.kernel@kolivas.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200705212344.27511.kernel@kolivas.org> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1321 Lines: 28 * Con Kolivas wrote: > > A suggestion for improvement: right now swap-prefetch does a small > > bit of swapin every 5 seconds and stays idle inbetween. Could this > > perhaps be made more agressive (optionally perhaps), if the system > > is not swapping otherwise? If block-IO level instrumentation is > > needed to determine idleness of block IO then that is justified too > > i think. > > Hmm.. The timer waits 5 seconds before trying to prefetch, but then > only stops if it detects any activity elsewhere. It doesn't actually > try to go idle in between but it doesn't take much activity to put it > back to sleep, hence detecting yet another "not quite idle" period and > then it goes to sleep again. I guess the sleep interval can actually > be changed as another tunable from 5 seconds to whatever the user > wanted. there was nothing else running on the system - so i suspect the swapin activity flagged 'itself' as some 'other' activity and stopped? The swapins happened in 4 bursts, separated by 5 seconds total idleness. Ingo - 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/