From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761433AbZEZX7u (ORCPT ); Tue, 26 May 2009 19:59:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756426AbZEZXy7 (ORCPT ); Tue, 26 May 2009 19:54:59 -0400 Received: from one.firstfloor.org ([213.235.205.2]:38617 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754721AbZEZXyv (ORCPT ); Tue, 26 May 2009 19:54:51 -0400 From: Andi Kleen To: linux-kernel@vger.kernel.org, hpa@zytor.com, x86@kernel.org Cc: Andi Kleen Subject: [PATCH 19/31] x86: MCE: Default to panic timeout for machine checks v2 Date: Wed, 27 May 2009 01:54:21 +0200 Message-Id: <0f7e10122c48b7988b1676be5e7fc75f2c561215.1243381848.git.ak@linux.intel.com> X-Mailer: git-send-email 1.6.0.2 In-Reply-To: <7efad2e5492abb8f94577a81c2ca397a968064d7.1243381848.git.ak@linux.intel.com> References: <1243382073-29338-1-git-send-email-andi@firstfloor.org> <6c6d1f8bbbd2312884dca5a5c75aa5f5a87dae4b.1243381848.git.ak@linux.intel.com> <1623cd9a1c77d35fc2044d72c4bfa1246e67a1c0.1243381848.git.ak@linux.intel.com> <723b3fe4e35063b123cee9658c24267287eeac07.1243381848.git.ak@linux.intel.com> <0301db6d6dabb8bcfaffe76a907a5036646c207d.1243381848.git.ak@linux.intel.com> <23417423c34ad949f53ebc947af8d18672a79a40.1243381848.git.ak@linux.intel.com> <347567c2ace55b336b1a43a67323ff8b86b80243.1243381848.git.ak@linux.intel.com> <3e29698799ad2c02429613323897a6e61a0a7d01.1243381848.git.ak@linux.intel.com> <34082fc262bae2f910f1a940622173445aea72cd.1243381848.git.ak@linux.intel.com> <37501061dc5d5581fefcaff92c2606e39cc61913.1243381848.git.ak@linux.intel.com> <10e478c24139e29e7e74529edd694858ec2fb7ea.1243381848.git.ak@linux.intel.com> <7efad2e5492abb8f94577a81c2ca397a968064d7.1243381848.git.ak@linux.intel.com> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andi Kleen Fatal machine checks can be logged to disk after boot, but only if the system did a warm reboot. That's unfortunately difficult with the default panic behaviour, which waits forever and the admin has to press the power button because modern systems usually miss a reset button. This clears the machine checks in the registers and make it impossible to log them. This patch changes the default for machine check panic to always reboot after 30s. Then the mce can be successfully logged after reboot. I believe this will improve machine check experience for any system running the X server. This is dependent on successfull boot logging of MCEs. This currently only works on Intel systems, on AMD there are quite a lot of systems around which leave junk in the machine check registers after boot, so it's disabled here. These systems will continue to default to endless waiting panic. v2: Only force panic timeout when it's shorter (H.Seto) Signed-off-by: Andi Kleen --- arch/x86/kernel/cpu/mcheck/mce.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index bf9bd6f..c31cbcf 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -82,6 +82,7 @@ static unsigned long notify_user; static int rip_msr; static int mce_bootlog = -1; static int monarch_timeout = -1; +static int mce_panic_timeout; static char trigger[128]; static char *trigger_argv[2] = { trigger, NULL }; @@ -203,6 +204,8 @@ static void wait_for_panic(void) local_irq_enable(); while (timeout-- > 0) udelay(1); + if (mce_panic_timeout < panic_timeout) + panic_timeout = mce_panic_timeout; panic("Panicing machine check CPU died"); } @@ -240,6 +243,8 @@ static void mce_panic(char *msg, struct mce *final, char *exp) printk(KERN_EMERG "Some CPUs didn't answer in synchronization\n"); if (exp) printk(KERN_EMERG "Machine check: %s\n", exp); + if (mce_panic_timeout < panic_timeout) + panic_timeout = mce_panic_timeout; panic(msg); } @@ -1100,6 +1105,8 @@ static void mce_cpu_quirks(struct cpuinfo_x86 *c) } if (monarch_timeout < 0) monarch_timeout = 0; + if (mce_bootlog != 0) + mce_panic_timeout = 30; } static void __cpuinit mce_ancient_init(struct cpuinfo_x86 *c) -- 1.6.0.2