From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965048AbWGKGPT (ORCPT ); Tue, 11 Jul 2006 02:15:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965168AbWGKGPT (ORCPT ); Tue, 11 Jul 2006 02:15:19 -0400 Received: from serv1.oss.ntt.co.jp ([222.151.198.98]:64645 "EHLO serv1.oss.ntt.co.jp") by vger.kernel.org with ESMTP id S965048AbWGKGPS (ORCPT ); Tue, 11 Jul 2006 02:15:18 -0400 Subject: Re: [Fastboot] [PATCH 1/3] stack overflow safe kdump (2.6.18-rc1-i386) - safe_smp_processor_id From: Fernando Luis =?ISO-8859-1?Q?V=E1zquez?= Cao To: Keith Owens Cc: "Eric W. Biederman" , akpm@osdl.org, James.Bottomley@steeleye.com, fastboot@lists.osdl.org, linux-kernel@vger.kernel.org, ak@suse.de In-Reply-To: <9807.1152593732@kao2.melbourne.sgi.com> References: <9807.1152593732@kao2.melbourne.sgi.com> Content-Type: text/plain Organization: =?UTF-8?Q?NTT=E3=82=AA=E3=83=BC=E3=83=97=E3=83=B3=E3=82=BD=E3=83=BC?= =?UTF-8?Q?=E3=82=B9=E3=82=BD=E3=83=95=E3=83=88=E3=82=A6=E3=82=A7?= =?UTF-8?Q?=E3=82=A2=E3=82=BB=E3=83=B3=E3=82=BF?= Date: Tue, 11 Jul 2006 15:15:14 +0900 Message-Id: <1152598514.2414.66.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi Keith! On Tue, 2006-07-11 at 14:55 +1000, Keith Owens wrote: > 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 Thank you for the links (I had forgotten about that thread) and comments! I prepared new patches and hopefully I got it right this time, Do they look good this time (PATCH 4/4 in particular)? Thank you in advance, Fernando