Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935226AbXFFUUg (ORCPT ); Wed, 6 Jun 2007 16:20:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932343AbXFFUU2 (ORCPT ); Wed, 6 Jun 2007 16:20:28 -0400 Received: from waste.org ([66.93.16.53]:41568 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752713AbXFFUU1 (ORCPT ); Wed, 6 Jun 2007 16:20:27 -0400 Date: Wed, 6 Jun 2007 15:19:55 -0500 From: Matt Mackall To: Ingo Molnar Cc: Rusty Russell , akpm@linux-foundation.org, Linux-kernel@vger.kernel.org Subject: Re: Interesting interaction between lguest and CFS Message-ID: <20070606201955.GG11115@waste.org> References: <20070604173710.GR11166@waste.org> <1181002734.25878.56.camel@localhost.localdomain> <1181010675.25878.140.camel@localhost.localdomain> <20070605041803.GO11115@waste.org> <20070605104353.GA7309@elte.hu> <20070605190806.GA18503@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070605190806.GA18503@elte.hu> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1538 Lines: 67 On Tue, Jun 05, 2007 at 09:08:06PM +0200, Ingo Molnar wrote: > > * Ingo Molnar wrote: > > > Matt, could you send me your .config too? Maybe i can reproduce it > > with your config. > > ok, got it (off-list) and you seem to have the default HZ=250. Could you > change it to HZ=1000 - does the delay get alot smaller? Well I'm too busy/lazy to reboot at the moment, but I've reproduced this behavior with the following: watchdelta.py: import time last = time.time() while 1: t = time.time() delta = t - last if delta > .5: print delta last = t $ nice -n 20 python watchdelta.py 0.696138858795 0.772134065628 0.852141141891 2.22020101547 0.600075960159 0.528147935867 0.556170940399 0.536160945892 0.572169065475 0.672204971313 0.576174974442 0.640056848526 0.548166036606 0.568286895752 0.544052124023 0.572114944458 0.534852027893 0.596146821976 0.552155971527 0.552098035812 0.564115047455 0.546761989594 0.63211107254 0.876178026199 0.584072828293 0.544088125229 0.760088920593 1.07612800598 0.552155017853 ... At load=1 (the first several lines), this prints out messages sporadically. At higher loads, every iteration is a >.5s delay. So it's probably not particular to lguest at all. -- Mathematics is the supreme nostalgia of our time. - 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/