Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754657Ab3D0FRN (ORCPT ); Sat, 27 Apr 2013 01:17:13 -0400 Received: from oproxy13-pub.unifiedlayer.com ([69.89.16.30]:41003 "HELO oproxy13-pub.unifiedlayer.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751677Ab3D0FRM (ORCPT ); Sat, 27 Apr 2013 01:17:12 -0400 Message-ID: <1367039826.12779.17.camel@Wailaba2> Subject: Re: [PATCH] process cputimer is moving faster than its corresponding clock From: Olivier Langlois To: KOSAKI Motohiro Cc: Frederic Weisbecker , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , schwidefsky@de.ibm.com, Steven Rostedt , LKML Date: Sat, 27 Apr 2013 01:17:06 -0400 In-Reply-To: <1367038943.12779.10.camel@Wailaba2> References: <1365184746.874.103.camel@Wailaba2> <1365593710.30071.52.camel@laptop> <1365608911.707.65.camel@Wailaba2> <1365763837.17140.52.camel@laptop> <1365782115.17140.68.camel@laptop> <1366951210.7911.28.camel@Wailaba2> <1366957639.7911.42.camel@Wailaba2> <517AD0AE.1030404@gmail.com> <1367027476.7911.60.camel@Wailaba2> <1367038943.12779.10.camel@Wailaba2> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.8.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Identified-User: {5686:box610.bluehost.com:olivierl:olivierlanglois.net} {sentby:smtp auth 173.178.230.31 authed with olivier@olivierlanglois.net} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 933 Lines: 34 > > > Also other factors to consider it is are you doing the test on a very > loaded system? What is your platform? > > I have tested it positively on 32 bit, 64 bits build on Atom N450 > > i7 first and second generation system. > > I did vary HZ from 300 to 1000 HZ, I tried the 3 three different > preemption models. > > With all these combinations, I still have the problem. > Kosaki, Also clocksource accuracy may affect the result. Here are mines: lano1106@hpmini ~ $ cat /sys/devices/system/clocksource/clocksource0/current_clocksource hpet lano1106@Wailaba2 ~/dev/linux/src/linux-3.8/kernel $ cat /sys/devices/system/clocksource/clocksource0/current_clocksource tsc -- 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/