From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sai Prakash Ranjan Subject: Re: [PATCH 0/6] Tracing register accesses with pstore and dynamic debug Date: Sat, 20 Oct 2018 12:02:37 +0530 Message-ID: <1d3ddbe3-d3ac-aa3e-fc9e-36739ddd0c91@codeaurora.org> References: <20181020052535.GA155509@joelaf.mtv.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181020052535.GA155509@joelaf.mtv.corp.google.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Joel Fernandes 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-m List-Id: linux-arm-msm@vger.kernel.org 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 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. Thanks, Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation 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_PASS 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 5192BC67863 for ; Sat, 20 Oct 2018 06:32:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D22F6214C3 for ; Sat, 20 Oct 2018 06:32:58 +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="f8oILOYn"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="CRrcUNmE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D22F6214C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.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 S1727043AbeJTOmR (ORCPT ); Sat, 20 Oct 2018 10:42:17 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:51886 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726261AbeJTOmR (ORCPT ); Sat, 20 Oct 2018 10:42:17 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id D89F860316; Sat, 20 Oct 2018 06:32:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1540017175; bh=KauYKAH5U7JGHNSWSnaT7rUGqKCw1oKiZpllrN3zkAU=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=f8oILOYnbfRDjOohJmhk9Qmswj8N/WnQIdzyPcDBKZ9X0LQrjwxiAw/wljYjV1Y/i 5ip0iQnxM6QBs1IYo9UrkDIBjQJSDpj7bV1FepnSHd5GSbtlLMyyCp5Fxj5wyb85K1 71Srs9BnU8ETCONDkTPK5wJwEH0QZbPSj/CnBUS0= Received: from [192.168.43.47] (unknown [223.227.22.91]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: saiprakash.ranjan@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 1580460316; Sat, 20 Oct 2018 06:32:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1540017174; bh=KauYKAH5U7JGHNSWSnaT7rUGqKCw1oKiZpllrN3zkAU=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=CRrcUNmE9fBLTF5clpSGtC76xyzSSSQZh3pyfcAqvGpMkwhZMgDBcb/6svlPiwGz3 2dx7iAx0A/OhPn0dlwNzuMjdx9Yn0CK5ztAQijkSAJ175TPdwxFNHEU4tsgtlK9GVW 39a+K2fYY9tEbaH5Fio2a/Be3LNK7djUYN0ve6/w= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 1580460316 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=saiprakash.ranjan@codeaurora.org Subject: Re: [PATCH 0/6] Tracing register accesses with pstore and dynamic debug To: Joel Fernandes 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 References: <20181020052535.GA155509@joelaf.mtv.corp.google.com> From: Sai Prakash Ranjan Message-ID: <1d3ddbe3-d3ac-aa3e-fc9e-36739ddd0c91@codeaurora.org> Date: Sat, 20 Oct 2018 12:02:37 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181020052535.GA155509@joelaf.mtv.corp.google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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. Thanks, Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation From mboxrd@z Thu Jan 1 00:00:00 1970 From: saiprakash.ranjan@codeaurora.org (Sai Prakash Ranjan) Date: Sat, 20 Oct 2018 12:02:37 +0530 Subject: [PATCH 0/6] Tracing register accesses with pstore and dynamic debug In-Reply-To: <20181020052535.GA155509@joelaf.mtv.corp.google.com> References: <20181020052535.GA155509@joelaf.mtv.corp.google.com> Message-ID: <1d3ddbe3-d3ac-aa3e-fc9e-36739ddd0c91@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 at 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 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. Thanks, Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation