Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758183AbXLHPma (ORCPT ); Sat, 8 Dec 2007 10:42:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754067AbXLHPmV (ORCPT ); Sat, 8 Dec 2007 10:42:21 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:54866 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752612AbXLHPmU (ORCPT ); Sat, 8 Dec 2007 10:42:20 -0500 Date: Sat, 8 Dec 2007 16:41:22 +0100 From: Ingo Molnar To: Michael Buesch Cc: Mark Lord , Guillaume Chazarain , stefano.brivio@polimi.it, Nick Piggin , Robert Love , linux-kernel@vger.kernel.org, Dave Jones , "Rafael J. Wysocki" , Thomas Gleixner , Andrew Morton , Len Brown Subject: Re: [PATCH] scheduler: fix x86 regression in native_sched_clock Message-ID: <20071208154122.GE30270@elte.hu> References: <20071207084559.GA11162@elte.hu> <200712081627.45937.mb@bu3sch.de> <20071208153327.GC30270@elte.hu> <200712081636.45828.mb@bu3sch.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200712081636.45828.mb@bu3sch.de> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 827 Lines: 28 * Michael Buesch wrote: > > i cannot see how. You can verify msleep by running something like this: > > > > while :; do time usleep 111000; done > > > > you should see a steady stream of: > > > > real 0m0.113s > > real 0m0.113s > > real 0m0.113s > > > > (on an idle system). If it fluctuates, with occasional longer delays, > > there's some timer problem present. > > Does the sleeping and timing use different time references? yes. But the real paranoid can do this from another box: while :; do time ssh testbox usleep 111000; done 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/