From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965214AbWGKE4V (ORCPT ); Tue, 11 Jul 2006 00:56:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965213AbWGKE4U (ORCPT ); Tue, 11 Jul 2006 00:56:20 -0400 Received: from omx2-ext.sgi.com ([192.48.171.19]:30094 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S965211AbWGKE4T (ORCPT ); Tue, 11 Jul 2006 00:56:19 -0400 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.1 From: Keith Owens To: Fernando Luis =?ISO-8859-1?Q?V=E1zquez?= Cao cc: "Eric W. Biederman" , akpm@osdl.org, James.Bottomley@steeleye.com, fastboot@lists.osdl.org, linux-kernel@vger.kernel.org, ak@suse.de Subject: Re: [Fastboot] [PATCH 1/3] stack overflow safe kdump (2.6.18-rc1-i386) - safe_smp_processor_id In-reply-to: Your message of "Tue, 11 Jul 2006 13:21:01 +0900." <1152591661.2414.11.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 11 Jul 2006 14:55:32 +1000 Message-ID: <9807.1152593732@kao2.melbourne.sgi.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Fernando Luis =?ISO-8859-1?Q?V=E1zquez?= Cao (on Tue, 11 Jul 2006 13:21:01 +0900) wrote: >That is a good idea, but I have on concern. In mach-default by default >we use __send_IPI_shortcut (no_broadcast==0) instead of send_IPI_mask. >Is it always safe to ignore the no_broadcast setting? In other words, >can __send_IPI_shortcut be replaced by send_IPI_mask safely? It is always safe to use send_IPI_mask. It is not used by default because of concerns that send_IPI_mask may be slower than using a broadcast, although I do not know if anybody has measurements to back up that concern. OTOH I can guarantee that sending NMI as a broadcast has problems, it breaks some Dell Xeon servers[1]. My fix was to never broadcast NMI, from 2.6.18-rc1 NMI_VECTOR always uses a mask[2] and crash was changed accordingly[3]. [1] http://marc.theaimsgroup.com/?t=114828920800003&r=1&w=2 [2] http://marc.theaimsgroup.com/?t=115103727400006&r=1&w=2 [3] http://marc.theaimsgroup.com/?t=115096703800003&r=1&w=2