Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753527AbXJWQLt (ORCPT ); Tue, 23 Oct 2007 12:11:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752284AbXJWQLl (ORCPT ); Tue, 23 Oct 2007 12:11:41 -0400 Received: from smtp4-g19.free.fr ([212.27.42.30]:52817 "EHLO smtp4-g19.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752299AbXJWQLk (ORCPT ); Tue, 23 Oct 2007 12:11:40 -0400 Message-ID: <471E1D3A.8000705@free.fr> Date: Tue, 23 Oct 2007 18:11:38 +0200 From: John Sigler User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.8) Gecko/20061108 SeaMonkey/1.0.6 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz Subject: How to debug complete kernel lock-ups Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2411 Lines: 74 Hello everyone, I have an x86 system with two PCI slots, in which I inserted two specialized output cards (Dektec DTA-105). http://www.dektec.com/Products/DTA-105/ (They provide an open source driver.) My problem is: when I write to the 4 ports (each card has 2 ports) "at the same time" (not really "at the same time" because I have a uni-processor system, so "within a short time frame" is more accurate) the system *completely* locks up. The manufacturer told me they had seen the problem in their lab. I'm just trying to provide some helpful debug output to speed up the process of fixing the problem :-) I've built a debug 2.6.22.1-rt9 kernel, hoping to get the kernel to dump something, anything. +CONFIG_KALLSYMS_ALL=y +CONFIG_PCI_DEBUG=y +CONFIG_DEBUG_DRIVER=y +CONFIG_PRINTK_TIME=y +CONFIG_MAGIC_SYSRQ=y +CONFIG_DEBUG_KERNEL=y +CONFIG_DEBUG_SHIRQ=y +CONFIG_DETECT_SOFTLOCKUP=y +CONFIG_DEBUG_SLAB=y +CONFIG_DEBUG_SLAB_LEAK=y +CONFIG_DEBUG_PREEMPT=y +CONFIG_DEBUG_RT_MUTEXES=y +CONFIG_DEBUG_PI_LIST=y +CONFIG_RT_MUTEX_TESTER=y +CONFIG_DEBUG_SPINLOCK=y +CONFIG_DEBUG_MUTEXES=y +CONFIG_DEBUG_LOCK_ALLOC=y +CONFIG_PROVE_LOCKING=y +CONFIG_LOCKDEP=y +CONFIG_TRACE_IRQFLAGS=y +CONFIG_DEBUG_SPINLOCK_SLEEP=y +CONFIG_DEBUG_LOCKING_API_SELFTESTS=y +CONFIG_STACKTRACE=y +CONFIG_PREEMPT_TRACE=y +CONFIG_DEBUG_BUGVERBOSE=y +CONFIG_DEBUG_INFO=y +CONFIG_FRAME_POINTER=y +CONFIG_FORCED_INLINING=y +CONFIG_DEBUG_STACKOVERFLOW=y +CONFIG_DEBUG_RODATA=y +CONFIG_4KSTACKS=y I've enabled the serial console, and used SysRq to bump the console level to 9 (I want everything, even KERN_DEBUG output). I've enabled the IO-APIC watchdog (nmi_watchdog=1). Once the system locks up, I get no output, no panic, no oops. The serial console is frozen, my ssh sessions are frozen. Suppose the PCI bus "crashes" (whatever that means) or locks up. Would that make the system completely unresponsive? The I/O does have to get to/from the south bridge, through the PCI bus AFAIU. I can imagine that a locked PCI bus would be slightly problematic. Does this mean I need some kind of PCI bus analyzer (i.e. hardware) at this point? Is there anything more I can try? Regards. - 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/