From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268899AbUIQQmB (ORCPT ); Fri, 17 Sep 2004 12:42:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268878AbUIQP0w (ORCPT ); Fri, 17 Sep 2004 11:26:52 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.105]:63697 "EHLO e5.ny.us.ibm.com") by vger.kernel.org with ESMTP id S268838AbUIQOms (ORCPT ); Fri, 17 Sep 2004 10:42:48 -0400 Date: Fri, 17 Sep 2004 20:23:50 +0530 From: Srivatsa Vaddagiri To: Dipankar Sarma Cc: Andrew Morton , hari@in.ibm.com, Rusty Russell , suparna@in.ibm.com, fastboot@osdl.org, ebiederm@xmission.com, litke@us.ibm.com, linux-kernel@vger.kernel.org, mbligh@aracnet.com Subject: Re: [Fastboot] Re: [PATCH][4/6]Register snapshotting before kexec boot Message-ID: <20040917145350.GA4750@in.ibm.com> Reply-To: vatsa@in.ibm.com References: <20040915125041.GA15450@in.ibm.com> <20040915125145.GB15450@in.ibm.com> <20040915125322.GC15450@in.ibm.com> <20040915125422.GD15450@in.ibm.com> <20040915125525.GE15450@in.ibm.com> <20040915142722.46088ad5.akpm@osdl.org> <20040916081138.GB4594@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040916081138.GB4594@in.ibm.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 16, 2004 at 08:41:13AM +0000, Dipankar Sarma wrote: > On Wed, Sep 15, 2004 at 02:27:22PM -0700, Andrew Morton wrote: > > Is dodgy wrt CPU hotplug, but there's not a lot we can do about that > > in this context, I expect. Which is a shame, given that CPU hotplug > > is a likely time at which to be taking a crashdump ;) > > If Hari disables preemption during this entire section of code, > he should be safe from CPU hotplug, AFAICS. The stop machine > threads will never get to run on that CPU. This will work for CPU remove, not CPU add, since the later is not atomic (yet). Rusty, do you think it would be worthwhile making CPU add atomic? I can give it a shot :) -- Thanks and Regards, Srivatsa Vaddagiri, Linux Technology Center, IBM Software Labs, Bangalore, INDIA - 560017