From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753489Ab1HAUl3 (ORCPT ); Mon, 1 Aug 2011 16:41:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14707 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753349Ab1HAUlY (ORCPT ); Mon, 1 Aug 2011 16:41:24 -0400 Date: Mon, 1 Aug 2011 16:41:14 -0400 From: Vivek Goyal To: Michael Holzheu Cc: ebiederm@xmission.com, mahesh@linux.vnet.ibm.com, hbabu@us.ibm.com, oomichi@mxs.nes.nec.co.jp, horms@verge.net.au, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: Re: [patch v2 04/10] kdump: Trigger kdump via panic notifier chain on s390 Message-ID: <20110801204114.GJ3805@redhat.com> References: <20110727125504.491183728@linux.vnet.ibm.com> <20110727125808.028895659@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110727125808.028895659@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 27, 2011 at 02:55:08PM +0200, Michael Holzheu wrote: > From: Michael Holzheu > > On s390 we have the possibility to configure actions that are executed in > case of a kernel panic. E.g. it is possible to automatically trigger an s390 > stand-alone dump. The actions are called via a panic notifier. We also want > to trigger kdump via the notifier call chain. Therefore this patch disables > for s390 the direct kdump invocation in the panic() function. Doesn't this reduce the reliability of the operation as you are assuming that panic notifier list is fine and not corrupted. There might be other generic notifiers registerd on panic notifier list too. So in your case, are there multiple subsystem registering for panic notifiers? If not, why not call crash_kexec() directly. Are there any other actions you want to take on panic then calling crash_kexec()? Thanks Vivek > > Signed-off-by: Michael Holzheu > --- > kernel/panic.c | 3 +++ > 1 file changed, 3 insertions(+) > > --- a/kernel/panic.c > +++ b/kernel/panic.c > @@ -84,9 +84,12 @@ NORET_TYPE void panic(const char * fmt, > /* > * If we have crashed and we have a crash kernel loaded let it handle > * everything else. > + * For s390 kdump is triggered via the panic notifier call chain. > * Do we want to call this before we try to display a message? > */ > +#if !defined(CONFIG_S390) > crash_kexec(NULL); > +#endif > > kmsg_dump(KMSG_DUMP_PANIC); >