From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753024AbXEAPzX (ORCPT ); Tue, 1 May 2007 11:55:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753049AbXEAPzX (ORCPT ); Tue, 1 May 2007 11:55:23 -0400 Received: from www.osadl.org ([213.239.205.134]:60387 "EHLO mail.tglx.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753023AbXEAPzV (ORCPT ); Tue, 1 May 2007 11:55:21 -0400 Subject: Re: [BUG] 2.6.21: Kernel won't boot with either/both of CONFIG_NO_HZ, CONFIG_HIGH_RES_TIMERS From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Mark Lord Cc: Daniel Walker , Linux Kernel , Linus Torvalds In-Reply-To: <46374B1D.6050509@rtr.ca> References: <46364EBC.5050804@rtr.ca> <46364F5A.2030208@rtr.ca> <463653A3.5040606@rtr.ca> <46367D7E.6060502@rtr.ca> <1177976798.12796.286.camel@imap.mvista.com> <463683A6.4010505@rtr.ca> <1178026458.5791.305.camel@localhost.localdomain> <4637419D.8010303@rtr.ca> <463741F1.7050706@rtr.ca> <1178027285.5791.307.camel@localhost.localdomain> <46374B1D.6050509@rtr.ca> Content-Type: text/plain Date: Tue, 01 May 2007 17:57:38 +0200 Message-Id: <1178035058.5791.333.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2007-05-01 at 10:13 -0400, Mark Lord wrote: > Of possible interest is that the bottom of the 25line screen capture > differs somewhat from the 50line capture.. see for yourself. > This is 100% consistent from boot to boot. > > Using CONFIG_DETECT_SOFTLOCKUP=y eliminates the problem, > so that's really got to be a huge clue, somehow ? I twisted my brain, why the watchdog thread might change the problem and I think I have a rough idea of the scenario. Can you apply the following patch, which prints out the CPU on which the kernel messages are generated and upload the screenshot when the hang happens ? Oh, please enable CONFIG_PRINTK_TIME or add "time" to the kernel commandline. tglx Index: linux-2.6.21/kernel/printk.c =================================================================== --- linux-2.6.21.orig/kernel/printk.c +++ linux-2.6.21/kernel/printk.c @@ -567,10 +567,11 @@ asmlinkage int vprintk(const char *fmt, t = printk_clock(); nanosec_rem = do_div(t, 1000000000); tlen = sprintf(tbuf, - "<%c>[%5lu.%06lu] ", + "<%c>[%5lu.%06lu] %d ", loglev_char, (unsigned long)t, - nanosec_rem/1000); + nanosec_rem/1000, + printk_cpu); for (tp = tbuf; tp < tbuf + tlen; tp++) emit_log_char(*tp);