From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754670AbYGKXnI (ORCPT ); Fri, 11 Jul 2008 19:43:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757526AbYGKXmx (ORCPT ); Fri, 11 Jul 2008 19:42:53 -0400 Received: from rv-out-0506.google.com ([209.85.198.229]:31767 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757104AbYGKXmw (ORCPT ); Fri, 11 Jul 2008 19:42:52 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=IQoAg2nvd7Ub5X0Egv8lFUPwLq91DAvzaqow6hkyGHi0A2kKN2up/H7oYzKdmxFpQQ Z/dwmQf/49MWdP9u1U2iqQuAR3rx2nUfb7YqJwc9QWd5H7YAc2pum1oNCb/8tJklGWMq vukbaIJJ407L0MTIkpYytcFmqQ+iqfE8JVjOY= Message-ID: Date: Sat, 12 Jul 2008 01:42:51 +0200 From: "Dmitry Adamushko" To: "Vegard Nossum" Subject: Re: v2.6.26-rc9: kernel BUG at kernel/sched.c:5858! Cc: Yanmin , "Rusty Russell" , "Ingo Molnar" , "Peter Zijlstra" , "Dhaval Giani" , "Gautham R Shenoy" , "Heiko Carstens" , miaox@cn.fujitsu.com, "Lai Jiangshan" , "Avi Kivity" , linux-kernel@vger.kernel.org In-Reply-To: <19f34abd0807111051q7b4a42b1l1f9ee05d45601ac3@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080710115954.GA3639@damson.getinternet.no> <19f34abd0807100604p70c2fec6geca65b2ba772dea@mail.gmail.com> <19f34abd0807100716k35e937batb4059f99fe46731b@mail.gmail.com> <19f34abd0807101249y24632b50h769a7af2c9514864@mail.gmail.com> <19f34abd0807102249t6b2e9e97l97bc5b22cc7709ef@mail.gmail.com> <19f34abd0807110404p5c588debu681aa466cc98ad08@mail.gmail.com> <19f34abd0807111051q7b4a42b1l1f9ee05d45601ac3@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2008/7/11 Vegard Nossum : > On Fri, Jul 11, 2008 at 1:04 PM, Vegard Nossum wrote: >> On Fri, Jul 11, 2008 at 11:02 AM, Dmitry Adamushko >> wrote: >>> Vegard, >>> >>> >>> regarding the first crash. Would you please run your test with the >>> following debugging patch and let me know its output? >>> >>> The apperance of " * [ pid ] comm (name), orig_cpu() ... " means we >>> hit a problematic case (with Miao Xie's patch it shouldn't crash). >>> >>> I see that you have CONFIG_SCHED_DEBUG=y so I'm also interested in >>> messages from sched_domain_debug() - "CPU# attaching ...". IOW, all >>> the kernel messages appearing while a cpu is going down and up. > [...] > >> Ok, now I tested it on my laptop (sorry, no serial console :-)) and I > > Now I tested using serial console, but nothing new: > > CPU0 attaching NULL sched-domain. > CPU1 attaching NULL sched-domain. > CPU0 attaching sched-domain: > domain 0: span 0-1 > groups: 0 1 > domain 1: span 0-1 > groups: 0-1 > CPU1 attaching sched-domain: > domain 0: span 0-1 > groups: 1 0 > domain 1: span 0-1 > groups: 0-1 hmm, sched-domains have been rebuilt too early. The soon-to-be-offline cpu #1 is included (as it's still in cpu_online_map presumably). > * [ 7 ] comm (ksoftirqd/1), orig_cpu (1), dst_cpu (1), cpu (1) Have you removed "__migrate_dead ... " printk messages? This one should be printed after __stop_machine_run(take_cpu_down, ...) and before migrate_live_tasks() takes place... so we would have seen "__migrate_dead..." message for ksoftirqd/1 a bit later, I guess. > CPU 1 is now offline migrate_live_tasks() should take place here... > * [ 1228 ] comm (kjournald), orig_cpu (0), dst_cpu (0), cpu (0) > * [ 3113 ] comm (klogd), orig_cpu (0), dst_cpu (0), cpu (0) I guess, these were migrated onto cpu#0 by migrate_live_tasks() but now try_to_wake_up() has been called for them. Due to the fact that cpu#1 is visible on the sched-domains, the load-balancer (select_task_rq()) picks it up erronneusly... bum. > > Vegard > -- Best regards, Dmitry Adamushko