From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934954Ab1KJPHR (ORCPT ); Thu, 10 Nov 2011 10:07:17 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:52334 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933924Ab1KJPHK (ORCPT ); Thu, 10 Nov 2011 10:07:10 -0500 Date: Thu, 10 Nov 2011 16:05:21 +0100 From: Ingo Molnar To: Yong Zhang Cc: John Stultz , LKML , David Daney , Thomas Gleixner , Chen Jie , zhangfx Subject: Re: [PATCH] clocksource: Avoid selecting mult values that might overflow when adjusted Message-ID: <20111110150521.GD29614@elte.hu> References: <1320264087-3413-1-git-send-email-john.stultz@linaro.org> <20111103211000.GA17895@elte.hu> <1320721740.10668.23.camel@work-vm> <20111108050259.GA13225@zhy> <1320788342.10668.49.camel@work-vm> <20111109014632.GA8124@zhy> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111109014632.GA8124@zhy> User-Agent: Mutt/1.5.21 (2010-09-15) 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=AWL,BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Yong Zhang wrote: > On Tue, Nov 08, 2011 at 01:39:02PM -0800, John Stultz wrote: > > On Tue, 2011-11-08 at 13:02 +0800, Yong Zhang wrote: > > > On Mon, Nov 07, 2011 at 07:09:00PM -0800, John Stultz wrote: > > > > Yong: Can you also give this a test run to make sure you don't see any > > > > problems? > > > > > > Still get warning (3.2-rc1 + your patch): > > > > > > [ 0.017009] ------------[ cut here ]------------ > > > [ 0.022156] WARNING: at /build/linux/kernel/time/timekeeping.c:828 do_timer+0x402/0x4e0() > > > [ 0.035917] Adjusting jiffies more then 11% (1024068096 vs 1024064000) > > > > Ah. We're tripping the warning here in early boot. We use jiffies as the > > default clocksource initially even before it is registered and the > > maxadj is then set. So since its null here, any adjustment triggers the > > warning. > > > > That's easy enough to avoid. Can you give this updated version a try to > > make sure I didn't miss anything else? > > This version boot well on my side. > > echo acpi_pm > /sys/devices/system/clocksource/clocksource0/current_clocksource > echo hpet > /sys/devices/system/clocksource/clocksource0/current_clocksource > > both work well. > > Tested-by: Yong Zhang John, mind sending a pull request for this, based against current tip:timers/core? I'm quite sure it will fix the boot warning i saw as well. Thanks, Ingo