From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755312Ab3KFTCk (ORCPT ); Wed, 6 Nov 2013 14:02:40 -0500 Received: from g4t0016.houston.hp.com ([15.201.24.19]:14607 "EHLO g4t0016.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750811Ab3KFTCj (ORCPT ); Wed, 6 Nov 2013 14:02:39 -0500 Date: Wed, 6 Nov 2013 12:02:32 -0700 From: jerry.hoemann@hp.com To: HATAYAMA Daisuke Cc: hpa@linux.intel.com, ebiederm@xmission.com, vgoyal@redhat.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, bp@alien8.de, akpm@linux-foundation.org, fengguang.wu@intel.com, jingbai.ma@hp.com Subject: Re: [PATCH v4 0/3] x86, apic, kexec: Add disable_cpu_apic kernel parameter Message-ID: <20131106190232.GA28119@anatevka.fc.hp.com> Reply-To: jerry.hoemann@hp.com References: <20131022150015.24240.39686.stgit@localhost6.localdomain6> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131022150015.24240.39686.stgit@localhost6.localdomain6> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 23, 2013 at 12:01:18AM +0900, HATAYAMA Daisuke wrote: > This patch set is to allow kdump 2nd kernel to wake up multiple CPUs > even if 1st kernel crashs on some AP, a continueing work from: > > [PATCH v3 0/2] x86, apic, kdump: Disable BSP if boot cpu is AP > https://lkml.org/lkml/2013/10/16/300. > > In this version, basic design has changed. Now users need to figure > out initial APIC ID of BSP in the 1st kernel and configures kernel > parameter for the 2nd kernel manually using disable_cpu_apic kernel > parameter to be newly introduced in this patch set. This design is > more flexible than the previous version in that we no longer have to > rely on ACPI/MP table to get initial APIC ID of BSP. > > Sorry, this patch set have not include in-source documentation > requested by Borislav Petkov yet, but I'll post it later separately, > which would be better to focus on documentation reviewing. > > ChangeLog > > v3 => v4) > > - Rebased on top of v3.12-rc6 > > - Basic design has been changed. Now users need to figure out initial > APIC ID of BSP in the 1st kernel and configures kernel parameter for > the 2nd kernel manually using disable_cpu_apic kernel parameter to > be newly introduced in this patch set. This design is more flexible > than the previous version in that we no longer have to rely on > ACPI/MP table to get initial APIC ID of BSP. > Daisuke, I have back ported version 4 of this patch to both a 2.6.32 and 3.0.80 based kernels and distros and tested on a prototype system. I have previously test version 1 & 3 as well.) The systems are configured to boot the capture kernel 8-way parallel. However, I am running makedumpfile single threaded. Panic is induced via "echo c > /proc/sysrq-trigger". This is done under various system loads and on random cpus. I have done over a thousand dumps total during this testing. I have seen no issues w/ the 3.0.80 dump testing on our proto. On the 2.6.32 testing on our proto, i have hit a low probability (< 5%) chance of the capture suffering a soft lockup hang during "Switching to clocksource hpet." I have not RCA'd this yet. Note, I have seen this issue on earlier version of the patch, so it is not specific to this version. I then tested the 2.6.32 port on a dl380. This worked without issue. Note, I have seen no issues related to this patch on our proto when booting the capture with a single processor. While I am still pursuing the issue of the 2.6.32 kernel on our proto, I believe this patch is good and should be accepted. thanks Jerry -- ---------------------------------------------------------------------------- Jerry Hoemann Software Engineer Hewlett-Packard/MODL 3404 E Harmony Rd. MS 57 phone: (970) 898-1022 Ft. Collins, CO 80528 FAX: (970) 898-XXXX email: jerry.hoemann@hp.com ----------------------------------------------------------------------------