Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751657AbZIWKlM (ORCPT ); Wed, 23 Sep 2009 06:41:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751378AbZIWKlM (ORCPT ); Wed, 23 Sep 2009 06:41:12 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:38271 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751182AbZIWKlL (ORCPT ); Wed, 23 Sep 2009 06:41:11 -0400 Date: Wed, 23 Sep 2009 12:41:00 +0200 From: Ingo Molnar To: Cyrill Gorcunov Cc: Chris Malley , Peter Zijlstra , Frederic Weisbecker , linux-kernel@vger.kernel.org, Steven Rostedt Subject: Re: perf sched record hangs machine Message-ID: <20090923104100.GA23941@elte.hu> References: <7863dc4c0909221409v7893bfd3o4b590d5951a233ba@mail.gmail.com> <20090922212453.GB6062@nowhere> <1253686585.7695.84.camel@twins> <20090923073253.GA18022@elte.hu> <20090923074028.GA3078@elte.hu> <7863dc4c0909230215u2fed3edciec84f93f24d3ae1@mail.gmail.com> <20090923092024.GA29323@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) 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=3.2.5 -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: 1778 Lines: 44 * Cyrill Gorcunov wrote: > On 9/23/09, Ingo Molnar wrote: > > > > * Chris Malley wrote: > > > >> 2009/9/23 Cyrill Gorcunov : > >> > > >> > Btw, meanwhile Chris may try to pass lapic boot-option in attempt to > >> > reenable apic via msr registers. Also (iirc) i feel we may be hiding > >> > errors if complete noop apic would be used since i belive we need to > >> > check out under which condition a particular operation is called and > >> > when apic is disabled it's mean we're switched to UP mode and > >> > inter-cpu interrupts are under suspicion too. Will take a look during > >> > ~6 hours ;) > >> > > >> > >> Hi Cyrill > >> > >> Heh, yes that just occurred to me as well. With the lapic boot option > >> I can't reproduce the problem, and get a good recording every time. > >> Don't know why the BIOS had disabled it (can't see any specific > >> option). > > > > Would still be important to fix the crash - there are boxes where lapics > > are disabled permanently and cannot be re-enabled. (plus most people > > dont touch their defaults and dont add funky boot options - so crashing > > is not an option) > > > > Ingo, Chris, could you try Peter's patch? It seems like what we need. It should fix the problem, but also the underlying uncleanliness should be fixed as well. We need an apic_none driver template with safe methods. Then all the scattered 'is the lapic enabled' open-coded checks of global flags can be removed. 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/