From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753226Ab1JLMzK (ORCPT ); Wed, 12 Oct 2011 08:55:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22220 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752528Ab1JLMzI (ORCPT ); Wed, 12 Oct 2011 08:55:08 -0400 Date: Wed, 12 Oct 2011 08:54:42 -0400 From: Don Zickus To: Ingo Molnar Cc: Andi Kleen , x86@kernel.org, LKML , Peter Zijlstra , Robert Richter , Andrew Morton , seiji.aguchi@hds.com, vgoyal@redhat.com, mjg@redhat.com, tony.luck@intel.com, gong.chen@intel.com, satoru.moriya@hds.com, avi@redhat.com Subject: Re: [PATCH 1/3] x86, reboot: Use NMI instead of REBOOT_VECTOR to stop cpus Message-ID: <20111012125442.GJ5795@redhat.com> References: <1318346686-12349-1-git-send-email-dzickus@redhat.com> <1318346686-12349-2-git-send-email-dzickus@redhat.com> <20111012073025.GI18618@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111012073025.GI18618@elte.hu> 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, Oct 12, 2011 at 09:30:25AM +0200, Ingo Molnar wrote: > > * Don Zickus wrote: > > > + if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback, > > + NMI_FLAG_FIRST, "smp_stop")) > > + return; /* return what? */ > > That comment looks a bit odd. Yeah, I copied it from the kdump code because it seemed relevant. The point was to express the paranoid concern, if we can't register the NMI handler for whatever reason, what happens!?. How do we explain to anyone we failed to shut down the other cpus? I can expand the comment to be more specific in the paranoia. I just wasn't sure the right way to handle that failure case. Thanks for your comments in the other patches, I'll work on those. Cheers, Don