From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail4.hitachi.co.jp ([133.145.228.5]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZMDZg-0003mv-Cr for kexec@lists.infradead.org; Mon, 03 Aug 2015 11:06:36 +0000 Message-ID: <55BF4B1F.9000602@hitachi.com> Date: Mon, 03 Aug 2015 20:06:07 +0900 From: Hidehiro Kawai MIME-Version: 1.0 Subject: Re: [RFC V2 PATCH 0/1] kexec: crash_kexec_post_notifiers boot option related fixes References: <20150724011615.6834.79628.stgit@softrs> In-Reply-To: <20150724011615.6834.79628.stgit@softrs> 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=infradead.org@lists.infradead.org To: "Eric W. Biederman" , Vivek Goyal Cc: linux-mips@linux-mips.org, Baoquan He , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, HATAYAMA Daisuke , Masami Hiramatsu , Daniel Walker , Andrew Morton , Ingo Molnar Hello Eric and Vivek, Do you have any comments? (2015/07/24 10:16), Hidehiro Kawai wrote: > This is a bugfix patch for crash_kexec_post_notifiers boot option > which allows users to call panic notifiers and kmsg dumpers before > kdump. > > This fixes one of the problems reported by Daniel Walker > (https://lkml.org/lkml/2015/6/24/44). > > Problem 1: > If crash_kexec_post_notifiers boot option is specified, some > shutting down process which assume other cpus are still alive > don't work properly. > > Problem 2 (addressed by this patch): > If crash_kexec_post_notifiers boot option is specified, register > information of other cpus are not saved to crash dumps. > > Following Vivek's opinion, this patch replaces smp_send_stop() > in panic() with suitable version for crash_kexec which saves > cpu states and other things like cleaning up VMX/SVM. Since this > needs architecture specific implementation and it's not so trivial, > this version only support for x86. So the problem 1, known to > happen on MIPS/OCTEON, is not addressed now. > > To keep the modification impact low, this patch doesn't change > the logic basically if crash_kexec_post_notifiers is not specified. > > Please note that crash_kexec() can be called directly without > entering panic(). Stopping other cpus functionality is still > needed in crash_kexec(). > > Changes in V2: > - Replace smp_send_stop() call with crash_kexec version which > saves cpu states and does cleanups instead of changing execution > flow > - Drop a fix for Problem 1 > - Drop other patches because they aren't needed anymore > > V1: https://lkml.org/lkml/2015/7/10/316 > > --- > > Hidehiro Kawai (1): > panic/x86: Replace smp_send_stop() with crash_kexec version > > > arch/x86/kernel/crash.c | 16 +++++++++++----- > kernel/panic.c | 29 +++++++++++++++++++++++------ > 2 files changed, 34 insertions(+), 11 deletions(-) > > -- Hidehiro Kawai Hitachi, Ltd. Research & Development Group _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 03 Aug 2015 13:06:19 +0200 (CEST) Received: from mail4.hitachi.co.jp ([133.145.228.5]:55440 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27011126AbbHCLGOlB9v0 (ORCPT ); Mon, 3 Aug 2015 13:06:14 +0200 Received: from mlsv1.hitachi.co.jp (unknown [133.144.234.166]) by mail4.hitachi.co.jp (Postfix) with ESMTP id 5B2532CF4C5; Mon, 3 Aug 2015 20:06:09 +0900 (JST) Received: from mfilter06.hitachi.co.jp by mlsv1.hitachi.co.jp (8.13.1/8.13.1) id t73B69vl029248; Mon, 3 Aug 2015 20:06:09 +0900 Received: from vshuts01.hitachi.co.jp (vshuts01.hitachi.co.jp [10.201.6.83]) by mfilter06.hitachi.co.jp (Switch-3.3.4/Switch-3.3.4) with ESMTP id t73B68xF022793; Mon, 3 Aug 2015 20:06:08 +0900 Received: from hsdlmain.sdl.hitachi.co.jp (unknown [133.144.14.194]) by vshuts01.hitachi.co.jp (Postfix) with ESMTP id C07112F003A; Mon, 3 Aug 2015 20:06:07 +0900 (JST) Received: from hsdlvgate2.sdl.hitachi.co.jp by hsdlmain.sdl.hitachi.co.jp (8.13.8/3.7W11021512) id t73B676s000897; Mon, 3 Aug 2015 20:06:07 +0900 X-AuditID: 85900ec0-9d7c9b9000001a57-bb-55bf4ae0c70c Received: from sdl99w.sdl.hitachi.co.jp (sdl99w.yrl.intra.hitachi.co.jp [133.144.14.250]) by hsdlvgate2.sdl.hitachi.co.jp (Symantec Mail Security) with ESMTP id 465FC236561; Mon, 3 Aug 2015 20:05:04 +0900 (JST) Received: from mailb.sdl.hitachi.co.jp (sdl99b.yrl.intra.hitachi.co.jp [133.144.14.197]) by sdl99w.sdl.hitachi.co.jp (Postfix) with ESMTP id 59B4B53C218; Mon, 3 Aug 2015 20:06:07 +0900 (JST) Received: from [10.198.220.34] (unknown [10.198.220.34]) by mailb.sdl.hitachi.co.jp (Postfix) with ESMTP id 2E9D1495B7E; Mon, 3 Aug 2015 20:06:07 +0900 (JST) Message-ID: <55BF4B1F.9000602@hitachi.com> Date: Mon, 03 Aug 2015 20:06:07 +0900 From: Hidehiro Kawai User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120604 Thunderbird/13.0 MIME-Version: 1.0 To: "Eric W. Biederman" , Vivek Goyal CC: Andrew Morton , linux-mips@linux-mips.org, Baoquan He , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, HATAYAMA Daisuke , Masami Hiramatsu , Daniel Walker , Ingo Molnar Subject: Re: [RFC V2 PATCH 0/1] kexec: crash_kexec_post_notifiers boot option related fixes References: <20150724011615.6834.79628.stgit@softrs> In-Reply-To: <20150724011615.6834.79628.stgit@softrs> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 48541 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: hidehiro.kawai.ez@hitachi.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips Hello Eric and Vivek, Do you have any comments? (2015/07/24 10:16), Hidehiro Kawai wrote: > This is a bugfix patch for crash_kexec_post_notifiers boot option > which allows users to call panic notifiers and kmsg dumpers before > kdump. > > This fixes one of the problems reported by Daniel Walker > (https://lkml.org/lkml/2015/6/24/44). > > Problem 1: > If crash_kexec_post_notifiers boot option is specified, some > shutting down process which assume other cpus are still alive > don't work properly. > > Problem 2 (addressed by this patch): > If crash_kexec_post_notifiers boot option is specified, register > information of other cpus are not saved to crash dumps. > > Following Vivek's opinion, this patch replaces smp_send_stop() > in panic() with suitable version for crash_kexec which saves > cpu states and other things like cleaning up VMX/SVM. Since this > needs architecture specific implementation and it's not so trivial, > this version only support for x86. So the problem 1, known to > happen on MIPS/OCTEON, is not addressed now. > > To keep the modification impact low, this patch doesn't change > the logic basically if crash_kexec_post_notifiers is not specified. > > Please note that crash_kexec() can be called directly without > entering panic(). Stopping other cpus functionality is still > needed in crash_kexec(). > > Changes in V2: > - Replace smp_send_stop() call with crash_kexec version which > saves cpu states and does cleanups instead of changing execution > flow > - Drop a fix for Problem 1 > - Drop other patches because they aren't needed anymore > > V1: https://lkml.org/lkml/2015/7/10/316 > > --- > > Hidehiro Kawai (1): > panic/x86: Replace smp_send_stop() with crash_kexec version > > > arch/x86/kernel/crash.c | 16 +++++++++++----- > kernel/panic.c | 29 +++++++++++++++++++++++------ > 2 files changed, 34 insertions(+), 11 deletions(-) > > -- Hidehiro Kawai Hitachi, Ltd. Research & Development Group