From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964969AbWFHULu (ORCPT ); Thu, 8 Jun 2006 16:11:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964973AbWFHULu (ORCPT ); Thu, 8 Jun 2006 16:11:50 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:17938 "EHLO spitz.ucw.cz") by vger.kernel.org with ESMTP id S964969AbWFHULt (ORCPT ); Thu, 8 Jun 2006 16:11:49 -0400 Date: Thu, 8 Jun 2006 20:11:35 +0000 From: Pavel Machek To: Don Zickus Cc: Jeremy Fitzhardinge , Andrew Morton , ak@suse.de, shaohua.li@intel.com, miles.lane@gmail.com, linux-kernel@vger.kernel.org Subject: Re: [2.6.17-rc5-mm2] crash when doing second suspend: BUG in arch/i386/kernel/nmi.c:174 Message-ID: <20060608201135.GC4006@ucw.cz> References: <4480C102.3060400@goop.org> <1149576246.32046.166.camel@sli10-desk.sh.intel.com> <20060606141755.GN2839@redhat.com> <200606061618.15415.ak@suse.de> <20060606214553.GB11696@redhat.com> <20060606151507.613edaad.akpm@osdl.org> <20060606230504.GC11696@redhat.com> <20060606162201.f0f9f308.akpm@osdl.org> <44860F7B.2040105@goop.org> <20060606234232.GD11696@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060606234232.GD11696@redhat.com> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > >All the above applies to suspend-to-disk. I don't know if suspend-to-RAM > > >shuts down the APs. > > > > > > > I'm using suspend-to-mem and it looks like its unplugging/replugging all > > the CPUs. > > > > The part of the question I don't quite understand is why this is > > considered per-CPU state? Surely NMI-watchdog is a system-wide thing? > > Or does this also tie into other uses of the performance registers which > > may be set per-CPU? > > The nmi watchdog is enable/disabled on a per-cpu basis. The fact that a > single switch turns all of them on/off is just convienance. Adding in > code to turn them on/off on a per-cpu basis just requires a simple user > interface. It has been talked about before to deal with NUMA systems. Does it make sense to run watchdog on cpu 1 but not on cpu 0? If user plugs cpu 2, should it get watchdog or not? If I unplug cpu 1 and plug it back, should it run watchdog or not? I believe it should be per-system thing. Pavel -- Thanks for all the (sleeping) penguins.