From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755434AbaFTPXW (ORCPT ); Fri, 20 Jun 2014 11:23:22 -0400 Received: from mail.skyhub.de ([78.46.96.112]:40895 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753166AbaFTPXU (ORCPT ); Fri, 20 Jun 2014 11:23:20 -0400 Date: Fri, 20 Jun 2014 17:23:12 +0200 From: Borislav Petkov To: Boris Ostrovsky Cc: tony.luck@intel.com, linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, mattieu.souchaud@free.fr Subject: Re: [PATCH] x86/mce: Don't unregister CPU hotplug notifier in error path Message-ID: <20140620152312.GB11391@pd.tnic> References: <1403274493-1371-1-git-send-email-boris.ostrovsky@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1403274493-1371-1-git-send-email-boris.ostrovsky@oracle.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 20, 2014 at 10:28:13AM -0400, Boris Ostrovsky wrote: > Commit 9c15a24b038f4d8da93a2bc2554731f8953a7c17 (x86/mce: Improve > mcheck_init_device() error handling) unregisters (or never registers) > MCE's hotplug notifier if an error is encountered. Well, mcheck_init_device() did encounter errors before that commit too, can you please go into detail on how exactly you're triggering this? Which error are you talking about exactly? Lemme guess: some xen special handling which baremetal doesn't need. > Since unplugging a CPU would normally result in the notifier deleting > MCE timer we are now left with the timer running if a CPU is removed on > a system where mcheck_init_device() had failed. > > If we later hotplug this CPU back we add this timer again in > mcheck_cpu_init()). Eventually the two timers start intefering with each > other, causing soft lockups or system hangs. > > We should leave the notifier always on and, in fact, set it up early > during the boot. We do leave it always on - we only unregister it if we've encountered an error. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --