From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757305AbYGINee (ORCPT ); Wed, 9 Jul 2008 09:34:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752066AbYGINe0 (ORCPT ); Wed, 9 Jul 2008 09:34:26 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:37614 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751508AbYGINeZ (ORCPT ); Wed, 9 Jul 2008 09:34:25 -0400 Date: Wed, 9 Jul 2008 15:33:58 +0200 From: Ingo Molnar To: Jeremy Fitzhardinge Cc: Nick Piggin , LKML , Jens Axboe , Peter Zijlstra , Christoph Lameter , Petr Tesarik , Virtualization , Xen devel , Thomas Friebel , Avi Kivity Subject: Re: [PATCH RFC 0/4] Paravirtual spinlocks Message-ID: <20080709133358.GA7005@elte.hu> References: <20080707190749.299430659@goop.org> <20080709122852.GA30579@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080709122852.GA30579@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) 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 the patches caused a boot hang with this config: http://redhat.com/~mingo/misc/config-Wed_Jul__9_14_47_04_CEST_2008.bad i have bisected it down to: commit e17b58c2e85bc2ad2afc07fb8d898017c2b75ed1 Author: Jeremy Fitzhardinge Date: Mon Jul 7 12:07:53 2008 -0700 xen: implement Xen-specific spinlocks i.e. applying that patch alone causes the hang. The hang happens in the ftrace self-test: initcall utsname_sysctl_init+0x0/0x19 returned 0 after 0 msecs calling init_sched_switch_trace+0x0/0x4c Testing tracer sched_switch: PASSED initcall init_sched_switch_trace+0x0/0x4c returned 0 after 167 msecs calling init_function_trace+0x0/0x12 Testing tracer ftrace: [hard hang] it should have continued like this: Testing tracer ftrace: PASSED initcall init_function_trace+0x0/0x12 returned 0 after 198 msecs calling init_irqsoff_tracer+0x0/0x14 Testing tracer irqsoff: PASSED initcall init_irqsoff_tracer+0x0/0x14 returned 0 after 3 msecs calling init_mmio_trace+0x0/0x12 initcall init_mmio_trace+0x0/0x12 returned 0 after 0 msecs note: ftrace is a user of raw spinlocks. Another speciality of the config is that it has paravirt enabled (obviously), and that it also has lock debugging enabled. Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH RFC 0/4] Paravirtual spinlocks Date: Wed, 9 Jul 2008 15:33:58 +0200 Message-ID: <20080709133358.GA7005@elte.hu> References: <20080707190749.299430659@goop.org> <20080709122852.GA30579@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20080709122852.GA30579@elte.hu> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jeremy Fitzhardinge Cc: Jens Axboe , Nick Piggin , Xen devel , Peter Zijlstra , Christoph Lameter , Petr Tesarik , LKML , Avi Kivity , Virtualization , Thomas Friebel List-Id: xen-devel@lists.xenproject.org the patches caused a boot hang with this config: http://redhat.com/~mingo/misc/config-Wed_Jul__9_14_47_04_CEST_2008.bad i have bisected it down to: commit e17b58c2e85bc2ad2afc07fb8d898017c2b75ed1 Author: Jeremy Fitzhardinge Date: Mon Jul 7 12:07:53 2008 -0700 xen: implement Xen-specific spinlocks i.e. applying that patch alone causes the hang. The hang happens in the ftrace self-test: initcall utsname_sysctl_init+0x0/0x19 returned 0 after 0 msecs calling init_sched_switch_trace+0x0/0x4c Testing tracer sched_switch: PASSED initcall init_sched_switch_trace+0x0/0x4c returned 0 after 167 msecs calling init_function_trace+0x0/0x12 Testing tracer ftrace: [hard hang] it should have continued like this: Testing tracer ftrace: PASSED initcall init_function_trace+0x0/0x12 returned 0 after 198 msecs calling init_irqsoff_tracer+0x0/0x14 Testing tracer irqsoff: PASSED initcall init_irqsoff_tracer+0x0/0x14 returned 0 after 3 msecs calling init_mmio_trace+0x0/0x12 initcall init_mmio_trace+0x0/0x12 returned 0 after 0 msecs note: ftrace is a user of raw spinlocks. Another speciality of the config is that it has paravirt enabled (obviously), and that it also has lock debugging enabled. Ingo