Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759546Ab2FGDCc (ORCPT ); Wed, 6 Jun 2012 23:02:32 -0400 Received: from mga02.intel.com ([134.134.136.20]:41279 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754746Ab2FGDCb (ORCPT ); Wed, 6 Jun 2012 23:02:31 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,352,1309762800"; d="scan'208";a="149194984" Message-ID: <4FD01933.7070000@intel.com> Date: Thu, 07 Jun 2012 11:00:03 +0800 From: ShuoX Liu Reply-To: shuox.liu@intel.com User-Agent: Mozilla/5.0 (X11; Linux i686; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: "linux-kernel@vger.kernel.org" CC: Borislav Petkov , Yanmin Zhang , "Luck, Tony" , Andrew Morton , "andi@firstfloor.org" , Ingo Molnar Subject: [PATCH v7 2/2] x86 mce: use new printk recursion disabling interface References: <4FC2E944.6060903@intel.com> <20120604171202.GA8533@x1.osrc.amd.com> <1338856360.14538.220.camel@ymzhang.sh.intel.com> <20120605081448.GA7097@liondog.tnic> <4FCDD72A.9030701@intel.com> <4FCDD78A.3070106@intel.com> <20120605151542.GA10669@x1.osrc.amd.com> <1338942965.14538.233.camel@ymzhang.sh.intel.com> <4FCF155B.3090705@intel.com> <4FCF160D.8010404@intel.com> <20120606152238.GA3874@x1.osrc.amd.com> <4FD01896.1010506@intel.com> In-Reply-To: <4FD01896.1010506@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1850 Lines: 54 From: ShuoX Liu On x86 machines, some times MCE happens just when kernel calls printk to output some log info to serial console, while usually MCE module in kernel is used to print out some hardware error information, such like bad cache or bad memory bank. That causes printk recursion and printk would omit MCE printk output. We hit it when running MTBF testing on Android ATOM mobiles. Here in print_mce, we choose to disable printk recursion to make sure MCE logs printed out. Signed-off-by: Yanmin Zhang Signed-off-by: ShuoX Liu --- arch/x86/kernel/cpu/mcheck/mce.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 2afcbd2..6056e94 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -242,6 +242,7 @@ static void print_mce(struct mce *m) { int ret = 0; + printk_recursion_check_disable(); pr_emerg(HW_ERR "CPU %d: Machine Check Exception: %Lx Bank %d: %016Lx\n", m->extcpu, m->mcgstatus, m->bank, m->status); @@ -275,10 +276,13 @@ static void print_mce(struct mce *m) * (if the CPU has an implementation for that) */ ret = atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m); - if (ret == NOTIFY_STOP) + if (ret == NOTIFY_STOP) { + printk_recursion_check_enable(); return; + } pr_emerg_ratelimited(HW_ERR "Run the above through 'mcelog --ascii'\n"); + printk_recursion_check_enable(); } #define PANIC_TIMEOUT 5 /* 5 seconds */ -- 1.7.1 -- 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/