From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1W3UZG-0006zi-TQ for kexec@lists.infradead.org; Wed, 15 Jan 2014 17:47:55 +0000 Date: Wed, 15 Jan 2014 12:47:14 -0500 From: Vivek Goyal Subject: Re: [RESEND PATCH v10] x86, apic, kexec, Documentation: Add disable_cpu_apicid kernel parameter Message-ID: <20140115174714.GG3180@redhat.com> References: <20140115064458.1545.38775.stgit@localhost6.localdomain6> <20140115170525.GF3180@redhat.com> <52D6C4B6.8010804@zytor.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <52D6C4B6.8010804@zytor.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: "H. Peter Anvin" Cc: fengguang.wu@intel.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, HATAYAMA Daisuke , bp@alien8.de, ebiederm@xmission.com, akpm@linux-foundation.org, hpa@linux.intel.com, jingbai.ma@hp.com On Wed, Jan 15, 2014 at 09:26:14AM -0800, H. Peter Anvin wrote: > On 01/15/2014 09:05 AM, Vivek Goyal wrote: > > > > I think this is a reasonable approach to solve the issue. Use a command > > line to not bring up specific cpu in second kernel which can create > > problems. > > > > Acked-by: Vivek Goyal > > > > hpa, I know you are not excited about this approach. If you made up your > > mind that this appoarch is not worth pursuing, please do suggest what > > would you like to see and we can give that a try. > > > > We want to solve this problem as on large memory machines saving dump can > > take lot of time and we want to bring up multiple cpus and speed up > > compression and save on dump time. > > > > I'm not excited about kdump's reliance on the command line, since it > seems to be a neverending source of trouble, simply because the command > line is fundamentally intended as a human interface. So in general, what are the alternatives? Either we figure out that kernel is booting as kdump kernel and do things differently. That seems even worse as what do we want in kdump kernel will change over a period of time. Other thing is that pass more information in bootparams. But that does not seem much different than command line to me. > However, this > seems relatively harmless in comparison with everything else and I am > much happier with saving the ID in the first kernel rather than trying > to guess if a currently-downed CPU is the BSP. So looks like you are alright with this patch. Can you please queue it up in your tree. Thanks Vivek _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec