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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no 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 943BFC32792 for ; Mon, 30 Sep 2019 13:53:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71A71216F4 for ; Mon, 30 Sep 2019 13:53:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731468AbfI3Nx5 convert rfc822-to-8bit (ORCPT ); Mon, 30 Sep 2019 09:53:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:41680 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730378AbfI3Nx5 (ORCPT ); Mon, 30 Sep 2019 09:53:57 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 90C6520842; Mon, 30 Sep 2019 13:53:56 +0000 (UTC) Date: Mon, 30 Sep 2019 09:53:54 -0400 From: Steven Rostedt To: Sodagudi Prasad Cc: pmladek@suse.com, sergey.senozhatsky@gmail.com, linux-kernel@vger.kernel.org Subject: Re: Time stamp value in printk records Message-ID: <20190930095354.08fa0d80@gandalf.local.home> In-Reply-To: <7d1aee8505b91c460fee347ed4204b9a@codeaurora.org> References: <7d1aee8505b91c460fee347ed4204b9a@codeaurora.org> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 30 Sep 2019 06:33:42 -0700 Sodagudi Prasad wrote: > Hi All, > > From Qualcomm side, we would like to check with upstream team about > adding Raw time stamp value to printk records. On Qualcomm soc, there > are various DSPs subsystems are there - for example audio, video and > modem DSPs. > Adding raw timer value(along with sched_clock()) in the printk record > helps in the following use cases – > 1) To find out which subsystem crashed first - Whether application > processor crashed first or DSP subsystem? > 2) If there are any system stability issues on the DSP side, what is the > activity on the APPS processor side during that time? > > Initially during the device boot up, printk shed_clock value can be > matched with timer raw value used on the dsp subsystem, but after APPS > processor suspends several times, we don’t have way to correlate the > time stamp value on the DSP and APPS processor. All timers(both apps > processor timer and dsp timers) are derived from globally always on > timer on Qualcomm soc, So keeping global timer raw values in printk > records and dsp logs help to correlate the activity of all the > processors in SoC. > > It would be great if upstream team adds common solution this problem if > all soc vendors would get benefit by adding raw timer value to printk > Hi Prasad, If you or someone you know would like to present patches for exactly what you would like to see, that would go a long way. -- Steve