From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755790AbZCMIwy (ORCPT ); Fri, 13 Mar 2009 04:52:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751502AbZCMIwp (ORCPT ); Fri, 13 Mar 2009 04:52:45 -0400 Received: from casper.infradead.org ([85.118.1.10]:55620 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751251AbZCMIwp (ORCPT ); Fri, 13 Mar 2009 04:52:45 -0400 Subject: Re: [PATCH, resend] eliminate spurious pointless WARN_ON()s From: Peter Zijlstra To: Andi Kleen Cc: Jan Beulich , Ingo Molnar , linux-kernel@vger.kernel.org In-Reply-To: <20090312134822.GI11935@one.firstfloor.org> References: <49B91A7E.76E4.0078.0@novell.com> <20090312134822.GI11935@one.firstfloor.org> Content-Type: text/plain Date: Fri, 13 Mar 2009 09:52:35 +0100 Message-Id: <1236934355.5188.203.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.25.92 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2009-03-12 at 14:48 +0100, Andi Kleen wrote: > 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. Oh? The only allocation that it does it at cpu-hotplug, where it allocates a cpu-mask thingy, and that's only a real allocation on NR_CPUS>64.