From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755408AbbGUKId (ORCPT ); Tue, 21 Jul 2015 06:08:33 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:37586 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755031AbbGUKIa (ORCPT ); Tue, 21 Jul 2015 06:08:30 -0400 Date: Tue, 21 Jul 2015 12:08:24 +0200 From: Ingo Molnar To: Borislav Petkov Cc: Tony Luck , X86-ML , LKML , ashok.raj@intel.com, gong.chen@linux.intel.com, Peter Zijlstra , Thomas Gleixner Subject: Re: [PATCH 1/7] x86/mce: Provide a lockless memory pool to save error records Message-ID: <20150721100824.GA26395@gmail.com> References: <20150716073948.GA13909@nazgul.tnic> <1437032661-15521-1-git-send-email-bp@suse.de> <20150721082949.GA2367@gmail.com> <20150721100330.GC32172@nazgul.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150721100330.GC32172@nazgul.tnic> 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 * Borislav Petkov wrote: > > So how are we going to report uncorrectable errors that forcibly crash/panic > > the system if we cannot use printk? How will the admin learn what was amiss? > > There's no change to that policy - we still panic for MCEs of MCE_PANIC_SEVERITY > and higher. And mce_panic() does use printk() to dump that critical information. Ok, I see: through mce_print(). > The gen_pool stuff is for MCEs for which the hw still raises an #MC exception > but the severity code determines that we don't need to panic but do recovery > action. > > However, we don't want to call printk() from the #MC exception handler since it > is NMI-like atomic context and printk is not NMI-safe (yet). Those printks are > issued later, in process context when we're done with the exception handler and > recovery action. Ok - no objections then. Thanks, Ingo