From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933741Ab0JSIz4 (ORCPT ); Tue, 19 Oct 2010 04:55:56 -0400 Received: from mgw-sa02.ext.nokia.com ([147.243.1.48]:52635 "EHLO mgw-sa02.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933658Ab0JSIzy (ORCPT ); Tue, 19 Oct 2010 04:55:54 -0400 Subject: Re: [RFC][Patch] Adding kmsg_dump() to reboot/halt/poweroff/emergency_restart path From: Artem Bityutskiy Reply-To: Artem.Bityutskiy@nokia.com To: ext KOSAKI Motohiro Cc: Seiji Aguchi , "simon.kagstrom@netinsight.net" , "David.Woodhouse@intel.com" , "anders.grafstrom@netinsight.net" , "akpm@linux-foundation.org" , "jason.wessel@windriver.com" , "jslaby@suse.cz" , "jmorris@namei.org" , "eparis@redhat.com" , "hch@lst.de" , "linux-kernel@vger.kernel.org" , "dle-develop@lists.sourceforge.net" , Satoru Moriya In-Reply-To: <20101019173303.A205.A69D9226@jp.fujitsu.com> References: <5C4C569E8A4B9B42A84A977CF070A35B2C11B4B724@USINDEVS01.corp.hds.com> <20101019173303.A205.A69D9226@jp.fujitsu.com> Content-Type: text/plain; charset="UTF-8" Organization: Nokia Date: Tue, 19 Oct 2010 11:51:12 +0300 Message-ID: <1287478272.9272.9.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 (2.30.3-1.fc13) Content-Transfer-Encoding: 8bit X-Nokia-AV: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2010-10-19 at 10:52 +0200, ext KOSAKI Motohiro wrote: > > Hi, > > > > Final messages from reboot, halt and poweroff aren't output to disk because klogd/syslogd > > has been killed and root file system has been turned read-only. > > > > Final messages from emergency_restart aren't output to disk as well because system may > > reboot before klogd/syslogd outputs messages to disk. > > > > Therefore, it is better to put kmsg_dumper in reboot/halt/poweroff/emergency_restart path. > > Any comments/advices are welcome. > > I think mtdoops user don't want to dump logs if a system reboot/poweroff > safely because mtd device have write count limitation. and they are main > user of kmsg_dump(). Right, at least this is how we use mtdoops - we log crashes. -- Best Regards, Artem Bityutskiy (Артём Битюцкий)