Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753286AbaF0JWg (ORCPT ); Fri, 27 Jun 2014 05:22:36 -0400 Received: from mail.skyhub.de ([78.46.96.112]:56291 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751127AbaF0JWe (ORCPT ); Fri, 27 Jun 2014 05:22:34 -0400 Date: Fri, 27 Jun 2014 11:22:27 +0200 From: Borislav Petkov To: Xie XiuQi Cc: "Naveen N. Rao" , "Chen, Gong" , tony.luck@intel.com, joe@perches.com, m.chehab@samsung.com, arozansk@redhat.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Li Bin Subject: Re: [PATCH v3 4/9] ACPI, x86: Extended error log driver for x86 platform Message-ID: <20140627092227.GA23153@pd.tnic> References: <1382084624-10857-1-git-send-email-gong.chen@linux.intel.com> <1382084624-10857-5-git-send-email-gong.chen@linux.intel.com> <52612BA4.2060906@linux.vnet.ibm.com> <53AD0275.7020003@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <53AD0275.7020003@huawei.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 27, 2014 at 01:34:45PM +0800, Xie XiuQi wrote: > The call graph is like this, > do_machine_check > -> mce_log > -> atomic_notifier_call_chain(&x86_mce_decoder_chain ...) > -> ... > -> extlog_print > -> print_extlog_rcd > -> __print_extlog_rcd > -> printk > > There's a logbuf_lock in printk. If logbuf_lock is held by other cpu, > it'll lead to an infinity spin here. Isn't it? Yes, but we want to take the risk and print something out before the machine dies instead of waiting to get into printk-safe context first and maybe corrupt state. Besides, there's work currently going on to make printk safe in atomic context so... -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- 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/