Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964770AbWARIIX (ORCPT ); Wed, 18 Jan 2006 03:08:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964880AbWARIIW (ORCPT ); Wed, 18 Jan 2006 03:08:22 -0500 Received: from thorn.pobox.com ([208.210.124.75]:54178 "EHLO thorn.pobox.com") by vger.kernel.org with ESMTP id S964770AbWARIIV (ORCPT ); Wed, 18 Jan 2006 03:08:21 -0500 Date: Wed, 18 Jan 2006 02:08:12 -0600 From: Nathan Lynch To: Ingo Molnar , Andrew Morton , anton@au1.ibm.com, linux-kernel@vger.kernel.org, michael@ellerman.id.au, linuxppc64-dev@ozlabs.org, serue@us.ibm.com, paulus@au1.ibm.com Subject: Re: 2.6.15-mm4 failure on power5 Message-ID: <20060118080812.GT2846@localhost.localdomain> References: <20060116063530.GB23399@sergelap.austin.ibm.com> <20060115230557.0f07a55c.akpm@osdl.org> <200601170000.58134.michael@ellerman.id.au> <20060116153748.GA25866@sergelap.austin.ibm.com> <20060116215252.GA10538@cs.umn.edu> <20060116170907.60149236.akpm@osdl.org> <20060117081749.GA10135@elte.hu> <20060117165244.GA23254@cs.umn.edu> <20060117165555.GA24562@cs.umn.edu> <20060118064050.GQ2846@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060118064050.GQ2846@localhost.localdomain> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1662 Lines: 33 Nathan Lynch wrote: > Dave C Boutcher wrote: > > On Tue, Jan 17, 2006 at 10:52:44AM -0600, Dave C Boutcher wrote: > > > Well, it turns out that I've been running with CONFIG_DEBUG_MUTEXES all > > > along...so no noise. My console output is a little different that > > > Serge's, so I think this is timing related. Also note that I'm dying in > > > the timer interrupt... > > > > duh... here's the backtrace > > 0:mon> t > > [c000000000577890] c0000000000034b4 decrementer_common+0xb4/0x100 > > --- Exception: 901 (Decrementer) at c0000000004627ec > > .__mutex_lock_interruptible_slowpath+0x3bc/0x4c4 > > [c000000000577c60] c000000000075064 .__lock_cpu_hotplug+0x44/0xa8 > > [c000000000577ce0] c000000000075600 .register_cpu_notifier+0x24/0x68 > > [c000000000577d70] c00000000052cd7c .do_init_bootmem+0x68c/0xab0 > > [c000000000577e50] c000000000522c84 .setup_arch+0x21c/0x2c0 > > [c000000000577ef0] c00000000051a538 .start_kernel+0x40/0x280 > > [c000000000577f90] c000000000008574 .hmt_init+0x0/0x8c > > The mutex debug code (debug_spin_unlock in kernel/mutex-debug.h) is > doing a local_irq_enable way before we're ready. Looks like not only the powerpc setup_arch code could trigger this -- rcu_init, init_timers, and sched_init all do register_cpu_notifier (and hence mutex_lock, therefore potentially enabling interrupts too early in the mutex debug case) before the initial local_irq_enable in start_kernel. - 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/