From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755002Ab0CQRxU (ORCPT ); Wed, 17 Mar 2010 13:53:20 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:59189 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754231Ab0CQRxS (ORCPT ); Wed, 17 Mar 2010 13:53:18 -0400 Date: Wed, 17 Mar 2010 18:53:11 +0100 From: Ingo Molnar To: mingo@redhat.com, hpa@zytor.com, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, tglx@linutronix.de Cc: linux-tip-commits@vger.kernel.org Subject: Re: [tip:core/rcu] rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU Message-ID: <20100317175311.GA5187@elte.hu> References: <1267311188-16603-1-git-send-email-paulmck@linux.vnet.ibm.com> <20100316110036.GA4554@elte.hu> <20100316110323.GA31038@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100316110323.GA31038@elte.hu> User-Agent: Mutt/1.5.20 (2009-08-17) 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=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 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 * Ingo Molnar wrote: > incidentally i have a RCU badness crash log from another box: > > [ 4.573332] initcall ipmi_init_msghandler_mod+0x0/0xd returned 0 after 0 usecs > [ 4.573332] calling init_ipmi_si+0x0/0x435 @ 1 > [ 4.573332] IPMI System Interface driver. > [ 4.573340] [] no_context+0x1fc/0x20b > [ 4.576672] [] ? ftrace_call+0x5/0x2b > [ 4.580021] [] __bad_area_nosemaphore+0x18c/0x1af > [ 4.583338] [] ? ftrace_call+0x5/0x2b > [ 4.586672] [] bad_area_nosemaphore+0x13/0x15 > [ 4.590005] [] do_page_fault+0x138/0x284 > [ 4.593354] [] page_fault+0x1f/0x30 I spent a few hours yesterday and today trying to track this down, but failed to bisect it. The crash is sporadic on many configs - which confused my bisection attempts. Sometimes it crashes only after 10 reboots. Was able to crash v2.6.30 as well, so it's an older bug. v2.6.29 was not testable on that box due to network driver problems so i stopped there. Ingo