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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A9761CA9EC0 for ; Tue, 29 Oct 2019 02:37:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 73C5B20862 for ; Tue, 29 Oct 2019 02:37:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="ie1MOmbg"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="ZFqIiXjP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730515AbfJ2Chs (ORCPT ); Mon, 28 Oct 2019 22:37:48 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:54466 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727775AbfJ2Chr (ORCPT ); Mon, 28 Oct 2019 22:37:47 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 00DC360D90; Tue, 29 Oct 2019 02:37:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1572316667; bh=SpU3CouSAnfBg2a8tqmWgQF4wwGKcI6vsq0WXo5HUl4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ie1MOmbgTAeYF+m8vDl1wmUKSVVpG9QzjFDquymWY+eL+3yB+55bJxNXC64SNRl2B lk1/4a7CPWoQGLPKucl7QYyKQ69X2p+tihcN/DrwjpT008rwhxkvviKF7lQCv3LYiF oMYb5FB8Dft367WR6p9pt0mQsclaEedxzsEFq1zQ= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 86D5A6092D; Tue, 29 Oct 2019 02:37:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1572316665; bh=SpU3CouSAnfBg2a8tqmWgQF4wwGKcI6vsq0WXo5HUl4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ZFqIiXjPMPXRBiaOU6BWJKwUP6zRSxUi3It+FSBQIJGrQczlInzJ2e41kUonmyE3+ HwK1ckJNXOtI7CSwQ0FVxzn3X3FRC3ZbWlkZdIKgV9Ep/QZCsDXjB/nnkmIRfXJqIp jLQE5fDcNDmdqT5N8i0qL9i4fJt03/bV2lpmKHuE= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 29 Oct 2019 10:37:45 +0800 From: cang@codeaurora.org To: Avri Altman Cc: "Winkler, Tomas" , asutoshd@codeaurora.org, nguyenb@codeaurora.org, rnayak@codeaurora.org, linux-scsi@vger.kernel.org, kernel-team@android.com, saravanak@google.com, salyzyn@google.com, Alim Akhtar , Pedro Sousa , "James E.J. Bottomley" , "Martin K. Petersen" , Evan Green , Janek Kotas , Stanley Chu , Bean Huo , Subhash Jadavani , Arnd Bergmann , Bjorn Andersson , open list Subject: Re: [PATCH v1 1/1] scsi: ufs: Add command logging infrastructure In-Reply-To: References: <1571808560-3965-1-git-send-email-cang@codeaurora.org> <5B8DA87D05A7694D9FA63FD143655C1B9DCF0AFE@hasmsx108.ger.corp.intel.com> Message-ID: <01eb3c55e35738f2853fbc7175a12eaa@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 2019-10-23 18:33, Avri Altman wrote: >> >> > Add the necessary infrastructure to keep timestamp history of >> > commands, events and other useful info for debugging complex issues. >> > This helps in diagnosing events leading upto failure. >> >> Why not use tracepoints, for that? > Ack on Tomas's comment. > Are there any pieces of information that you need not provided by the > upiu tracer? > > Thanks, > Avri In extreme cases, when the UFS runs into bad state, system may crash. There may not be a chance to collect trace. If trace is not collected and failure is hard to be reproduced, some command logs prints would be very helpful to help understand what was going on before we run into failure. Thanks, Can Guo