Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756753AbYCVOWV (ORCPT ); Sat, 22 Mar 2008 10:22:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754557AbYCVOWL (ORCPT ); Sat, 22 Mar 2008 10:22:11 -0400 Received: from one.firstfloor.org ([213.235.205.2]:36005 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755523AbYCVOWK (ORCPT ); Sat, 22 Mar 2008 10:22:10 -0400 Date: Sat, 22 Mar 2008 15:25:02 +0100 From: Andi Kleen To: Thomas Gleixner Cc: Gabriel C , Gabriel C , "Rafael J. Wysocki" , LKML , Adrian Bunk , Andrew Morton , Linus Torvalds , Natalie Protasevich , andi-bz@firstfloor.org, Ingo Molnar Subject: Re: 2.6.25-rc5-git6: Reported regressions from 2.6.24 Message-ID: <20080322142502.GA10687@one.firstfloor.org> References: <47E3E66F.9040006@frugalware.org> <47E3FA4F.9060509@frugalware.org> <47E40B1C.30407@frugalware.org> <47E420C5.1050407@frugalware.org> <47E42FAB.6000906@frugalware.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1148 Lines: 29 > CPU0 runs the watchdog timer and schedules it on CPU1. > > With NO_HZ enabled CPU1 is in a long idle sleep. At this point of the > boot process there is probably no timer pending on CPU1, which means > the idle sleep is infinite. > > Now some time later CPU1 gets woken by an interrupt/IPI and runs the > timer wheel. At this point the pm_timer which is the reference clock > has already wrapped around, so the watchdog thinks that there is a In my old original own noidletick code I simply limited all sleeps to below the wrap around of the primary timer. Wouldn't something like that work? In the case of the watchdog i guess it would need to be limited to the wrap around of multiple timers, at least all that are used by the watchdog. I'm not sure just doing this for add_timer_on() only is correct. After all it could affect any other code not run by add_timer_on() couldn't it? -Andi -- 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/