From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753628AbcHJSnj (ORCPT ); Wed, 10 Aug 2016 14:43:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37822 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753336AbcHJSnh (ORCPT ); Wed, 10 Aug 2016 14:43:37 -0400 Date: Wed, 10 Aug 2016 17:16:00 +0800 From: Dave Young To: Zhou Wenjian Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, bhe@redhat.com, vgoyal@redhat.com, corbet@lwn.net, kexec@lists.infradead.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v5 2/2] Documentation: kdump: add description of enable multi-cpus support Message-ID: <20160810091600.GD3147@dhcp-128-65.nay.redhat.com> References: <1470810145-8389-1-git-send-email-zhouwj-fnst@cn.fujitsu.com> <1470810145-8389-3-git-send-email-zhouwj-fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1470810145-8389-3-git-send-email-zhouwj-fnst@cn.fujitsu.com> User-Agent: Mutt/1.6.2 (2016-07-01) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 10 Aug 2016 09:16:08 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/10/16 at 02:22pm, Zhou Wenjian wrote: > multi-cpu support is useful to improve the performance of kdump in > some cases. So add the description of enable multi-cpu support in > dump-capture kernel. > > Signed-off-by: Zhou Wenjian > Acked-by: Baoquan He > --- > Documentation/kdump/kdump.txt | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt > index b474060..9c8d18e 100644 > --- a/Documentation/kdump/kdump.txt > +++ b/Documentation/kdump/kdump.txt > @@ -396,6 +396,13 @@ Notes on loading the dump-capture kernel: > Note, though maxcpus always works, we should replace it by nr_cpus to > save memory if supported by the current ARCH, such as x86. > > +* We should enable multi-cpu support in dump-capture kernel if we intend > + to use multi-thread programs with it, such as parallel dump feature of > + makedumpfile. Otherwise, the multi-thread program may have a great > + performance degradation. To enable multi-cpu support, we should bring up > + a SMP dump-capture kernel and specify maxcpus\nr_cpus, disable_cpu_apic=[X] > + options while loading it. Again, please replace "we" with second person "you".. > + > * For s390x there are two kdump modes: If a ELF header is specified with > the elfcorehdr= kernel parameter, it is used by the kdump kernel as it > is done on all other architectures. If no elfcorehdr= kernel parameter is > -- > 1.8.3.1 > > >