From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935759Ab3DITVc (ORCPT ); Tue, 9 Apr 2013 15:21:32 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:41017 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759304Ab3DITVb (ORCPT ); Tue, 9 Apr 2013 15:21:31 -0400 Message-ID: <51646A15.8060004@oracle.com> Date: Tue, 09 Apr 2013 13:20:53 -0600 From: Khalid Aziz Organization: Oracle Corp User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: "Luck, Tony" CC: "bp@alien8.de" , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "x86@kernel.org" , "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] x86, mce: Print warning if MCE handler fails to register /dev/mcelog References: <1365531571.8447.4.camel@concerto> <3908561D78D1C84285E8C5FCA982C28F1EA41C2B@ORSMSX104.amr.corp.intel.com> In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F1EA41C2B@ORSMSX104.amr.corp.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/09/2013 12:30 PM, Luck, Tony wrote: > - misc_register(&mce_chrdev_device); > + if (misc_register(&mce_chrdev_device) != 0) > + pr_warn("Failed to register mcelog device\n"); > > Did this actually happen to you? Or is this just "good practice" to check the > return value from misc_register? > No, I did not see this happen. It is just "good practice". If it were to happen, mcelog daemon would fail to get any mce records and it will not be easy to figure out what happened. Most other places in kernel where misc_register() is called, do check for return code and take action if it fails. -- Khalid