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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 22381C67863 for ; Sat, 20 Oct 2018 16:27:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD0ED2157C for ; Sat, 20 Oct 2018 16:27:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="Bh/kc1mx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DD0ED2157C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=joelfernandes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727666AbeJUAiX (ORCPT ); Sat, 20 Oct 2018 20:38:23 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:34341 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727641AbeJUAiW (ORCPT ); Sat, 20 Oct 2018 20:38:22 -0400 Received: by mail-pl1-f193.google.com with SMTP id f18-v6so17205225plr.1 for ; Sat, 20 Oct 2018 09:27:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=g8F3M6b4IChNzSESlZQJagl85VYvRdNHyowGbl1Xuu4=; b=Bh/kc1mxZw8WFca127OX8MJO5lSN+ZXqTKFmhqS/CXGJ1Fz23iaYhwARoJVE2FMDo4 XU3ukuEB/3G5/ljk4xqQtCkobqwJLOKGyvL3LDPZ7x8f5fL6VwG1sPg7XxizcX2NHYpo R5g2gWcLXWicEFwVf5yY+dAmJfZtGzI3IMDLM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=g8F3M6b4IChNzSESlZQJagl85VYvRdNHyowGbl1Xuu4=; b=ZGJrk4ndDh49hn6OBred5bDXR1tfPMja9a4+8dmrZSnhZu0KzMUX+LqDIa4BzEMr9T QApk7a6sp/2kdPZYnbThA+TnsYPK7K/kGUP+/efN7c7jTLmNWVNHC5rvHrUO80B4rMyc bYd+50A4PEds7boLEUX6x73sh3ZY9j4L5MhQA0lTA4ji9i7hTKHqYDc6NOplvEn6e+hi huaQ9lk9X9kELJC6lvmxZBVfI9dP+PlGHobQ4yqz3W5/VgmtS8vmTRF26JQOVufOn69I t4yQqQYY4J0dvdyDjg+K6il4ahZ6dhM+X73qg+VAxaZNwp3opdI9fjxhR9+VEWsazxLr NY+w== X-Gm-Message-State: ABuFfoipVM/HOSK0j7APNATn5l9sSlXWh4Vqy/WmvcwYEOgUEYQonGzN NOGh4Cx0pJcA/w1Pde6nO+bjfQ== X-Google-Smtp-Source: ACcGV61bqwF6I1GOMEC0nSsxBNTLLKimqtbWnVSnr6twB75n9gWgjb1YFvYFvu5O1y43t8n2RHjjJg== X-Received: by 2002:a17:902:6b81:: with SMTP id p1-v6mr38272117plk.162.1540052842056; Sat, 20 Oct 2018 09:27:22 -0700 (PDT) Received: from localhost ([2620:0:1000:1601:3aef:314f:b9ea:889f]) by smtp.gmail.com with ESMTPSA id 74-v6sm42242444pfx.182.2018.10.20.09.27.20 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 20 Oct 2018 09:27:20 -0700 (PDT) Date: Sat, 20 Oct 2018 09:27:19 -0700 From: Joel Fernandes To: Sai Prakash Ranjan Cc: Steven Rostedt , Ingo Molnar , Laura Abbott , Kees Cook , Anton Vorontsov , Rob Herring , devicetree@vger.kernel.org, Colin Cross , Jason Baron , Tony Luck , Arnd Bergmann , Catalin Marinas , Will Deacon , Masami Hiramatsu , Joe Perches , Jim Cromie , Rajendra Nayak , Vivek Gautam , Sibi Sankar , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Greg Kroah-Hartman , Ingo Molnar , Tom Zanussi , Prasad Sodagudi , tsoni@codeaurora.org, Bryan Huntsman , Tingwei Zhang , tkjos@google.com Subject: Re: [PATCH 0/6] Tracing register accesses with pstore and dynamic debug Message-ID: <20181020162719.GA49955@joelaf.mtv.corp.google.com> References: <20181020052535.GA155509@joelaf.mtv.corp.google.com> <1d3ddbe3-d3ac-aa3e-fc9e-36739ddd0c91@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1d3ddbe3-d3ac-aa3e-fc9e-36739ddd0c91@codeaurora.org> 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 Sat, Oct 20, 2018 at 12:02:37PM +0530, Sai Prakash Ranjan wrote: > On 10/20/2018 10:55 AM, Joel Fernandes wrote: > > On Sun, Sep 09, 2018 at 01:57:01AM +0530, Sai Prakash Ranjan wrote: > > > Hi, > > > > > > This patch series adds Event tracing support to pstore and is continuation > > > to the RFC patch introduced to add a new tracing facility for register > > > accesses called Register Trace Buffer(RTB). Since we decided to not introduce > > > a separate framework to trace register accesses and use existing framework > > > like tracepoints, I have moved from RFC. Details of the RFC in link below: > > > > > > Link: https://lore.kernel.org/lkml/cover.1535119710.git.saiprakash.ranjan@codeaurora.org/ > > > > > > MSR tracing example given by Steven was helpful in using tracepoints for > > > register accesses instead of using separate trace. But just having these > > > IO traces would not help much unless we could have them in some persistent > > > ram buffer for debugging unclocked access or some kind of bus hang or an > > > unexpected reset caused by some buggy driver which happens a lot during > > > initial development stages. By analyzing the last few entries of this buffer, > > > we could identify the register access which is causing the issue. > > > > Hi Sai, > > > > I wanted to see if I could make some time to get your patches working. We are > > hitting usecases that need something like this as well. Basically devices > > hanging and then the ramdump does not tell us much, so in this case pstore > > events can be really helpful. This usecase came up last year as well. > > > > Anyway while I was going through your patches, I cleaned up some pstore code > > as well and I have 3 more patches on top of yours for this clean up. I prefer > > we submit the patches together and sync our work together so that there is > > least conflict. > > > > Here's my latest tree: > > https://github.com/joelagnel/linux-kernel/commits/pstore-events > > (note that I have only build tested the patches since I just wrote them and > > its quite late in the night here ;-)) > > > > Hi Joel, > > Thanks for looking into this. Sure, I will be happy to sync up with you on Thanks. And added a fourth patch in the tree too. > this. I can test your additional patches on top of my pstore patches. BTW, > I'm still stuck at copying binary record into pstore and then extract it > during read time. Seems like I'm missing something. Sure, push your latest somewhere and let me know. I'll try to get you unstuck. thanks, - Joel