From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756009AbZCLN3E (ORCPT ); Thu, 12 Mar 2009 09:29:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754348AbZCLN2x (ORCPT ); Thu, 12 Mar 2009 09:28:53 -0400 Received: from one.firstfloor.org ([213.235.205.2]:55708 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753891AbZCLN2w (ORCPT ); Thu, 12 Mar 2009 09:28:52 -0400 Date: Thu, 12 Mar 2009 14:48:22 +0100 From: Andi Kleen To: Jan Beulich Cc: Ingo Molnar , Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [PATCH, resend] eliminate spurious pointless WARN_ON()s Message-ID: <20090312134822.GI11935@one.firstfloor.org> References: <49B91A7E.76E4.0078.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49B91A7E.76E4.0078.0@novell.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 12, 2009 at 01:21:50PM +0000, Jan Beulich wrote: > Namely during early boot, the panic() or BUG() paths may end up in > smp_call_function_*() with just a single online CPU. In that situation > the warnings generated are not only meaningless, but also result in > relevant output being cluttered. I actually have patches that just fix panic/shutdown to never call smp_call_function(), but use an own vector. It does all kinds of other things too that are not appropiate in panic, like allocating memory. My main motivation was for machine checks which currently always run into WARN_Ons when they panic with interrupts off, but as you say there are other cases too like early boot. Will post them later today or tomorrow. -Andi