Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755276AbXLHPPT (ORCPT ); Sat, 8 Dec 2007 10:15:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752269AbXLHPPF (ORCPT ); Sat, 8 Dec 2007 10:15:05 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:41076 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752278AbXLHPPD (ORCPT ); Sat, 8 Dec 2007 10:15:03 -0500 Date: Sat, 8 Dec 2007 16:13:41 +0100 From: Ingo Molnar To: Mark Lord Cc: Guillaume Chazarain , stefano.brivio@polimi.it, Nick Piggin , Robert Love , linux-kernel@vger.kernel.org, Dave Jones , "Rafael J. Wysocki" , Michael Buesch , Thomas Gleixner , Andrew Morton , Len Brown Subject: Re: [PATCH] scheduler: fix x86 regression in native_sched_clock Message-ID: <20071208151341.GA25413@elte.hu> References: <20071207084559.GA11162@elte.hu> <200712072213.06530.nickpiggin@yahoo.com.au> <20071207122310.maqkoxlb4gsg4ggc@webmail.polimi.it> <20071207122516.GA25115@elte.hu> <20071207123509.GA28676@elte.hu> <20071207124034.GA30052@elte.hu> <20071207145418.GA22277@elte.hu> <20071207174649.39c9198d@inria.fr> <20071207175754.GB19173@elte.hu> <475AB2FD.30600@rtr.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <475AB2FD.30600@rtr.ca> 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: 1202 Lines: 34 * Mark Lord wrote: > Ingo Molnar wrote: >> ... >> thanks. I do get the impression that most of this can/should wait until >> 2.6.25. The patches look quite dangerous. > .. > > I confess to not really trying hard to understand everything in this > thread, but the implication seems to be that this bug might affect > udelay() and possibly jiffies ? no, it cannot affect jiffies. (jiffies was a red herring all along) udelay() cannot be affected either - sched_clock() has no effect on udelay(). _But_, when there are TSC problems then tsc based udelay() suffers too so the phenomenons may _seem_ related. > If so, then fixing it has to be a *must* for 2.6.24, as otherwise > we'll get all sorts of one-in-while odd driver bugs.. like maybe these > two for starters: > > [Bug 9492] 2.6.24: false double-clicks from USB mouse > [Bug 9489] 20000+ wake-ups/second in 2.6.24 iirc these high rate wakeups happened on 2.6.22 too. 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/