From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02BB0C433E0 for ; Mon, 8 Jun 2020 08:06:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D084220656 for ; Mon, 8 Jun 2020 08:06:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729092AbgFHIGc (ORCPT ); Mon, 8 Jun 2020 04:06:32 -0400 Received: from mx2.suse.de ([195.135.220.15]:53630 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728956AbgFHIGb (ORCPT ); Mon, 8 Jun 2020 04:06:31 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id EE344B01D; Mon, 8 Jun 2020 08:06:32 +0000 (UTC) Date: Mon, 8 Jun 2020 10:06:27 +0200 From: Petr Mladek To: Pavel Tatashin Cc: jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com, keescook@chromium.org, anton@enomsg.org, ccross@android.com, tony.luck@intel.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kexec: dump kmessage before machine_kexec Message-ID: <20200608080627.GD5099@linux-b0ei> References: <20200605194642.62278-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200605194642.62278-1-pasha.tatashin@soleen.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 2020-06-05 15:46:42, Pavel Tatashin wrote: > kmsg_dump(KMSG_DUMP_SHUTDOWN) is called before > machine_restart(), machine_halt(), machine_power_off(), the only one that > is missing is machine_kexec(). > > The dmesg output that it contains can be used to study the shutdown > performance of both kernel and systemd during kexec reboot. > > Here is example of dmesg data collected after kexec: > > root@dplat-cp22:~# cat /sys/fs/pstore/dmesg-ramoops-0 | tail > ... > <6>[ 70.914592] psci: CPU3 killed (polled 0 ms) > <5>[ 70.915705] CPU4: shutdown > <6>[ 70.916643] psci: CPU4 killed (polled 4 ms) > <5>[ 70.917715] CPU5: shutdown > <6>[ 70.918725] psci: CPU5 killed (polled 0 ms) > <5>[ 70.919704] CPU6: shutdown > <6>[ 70.920726] psci: CPU6 killed (polled 4 ms) > <5>[ 70.921642] CPU7: shutdown > <6>[ 70.922650] psci: CPU7 killed (polled 0 ms) > > Signed-off-by: Pavel Tatashin Reviewed-by: Petr Mladek Best Regards, Petr