From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 254BBA051A; Fri, 17 Jan 2020 11:44:13 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 5B4571D381; Fri, 17 Jan 2020 11:44:12 +0100 (CET) Received: from us-smtp-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by dpdk.org (Postfix) with ESMTP id AA18D1D381 for ; Fri, 17 Jan 2020 11:44:11 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579257851; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=c3+iseNd/aWK2t+dG2KuSWTDJylEPLZk4BJk2nOqWDo=; b=embY7vEgdMnrXCI3UswK7zRYlTEtYdzwIgShaPOUpcA/hHgFekMG91a/JYZcd5hCGM3jPK Z9i+1pk2itI45XLF4L9HMHLHqNE6tKKuvquTT0yiugqhAfN3N5xNgWuFyMtXMs5Vne+GhK jV0IZMhaJMzaQ7+g5zGt3LBLu5AuFwk= Received: from mail-vk1-f199.google.com (mail-vk1-f199.google.com [209.85.221.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-14-djzsRohsN_ywNmFh4ujQbA-1; Fri, 17 Jan 2020 05:44:03 -0500 Received: by mail-vk1-f199.google.com with SMTP id h18so9573101vkh.13 for ; Fri, 17 Jan 2020 02:44:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=c3+iseNd/aWK2t+dG2KuSWTDJylEPLZk4BJk2nOqWDo=; b=Av1Pd8Nl7lUUnDe393AUOGukpMFsFGHekJPM269LHulJBynQcUApDf1Ve/F3T5cTdo FZgLyUqYWdIyAli8qJB6WtGkBRA1TLGG0GubJZ2j9zDIKUkxy8T3YULh39Uj5VOv7BlS aRIzV3HlCx2r7dQQxoBwJkph3xTv3jICfmw9tbz31B/G25ejb2WnONHazmpc0vIqQai7 i2oZs3Stf3Q72NGZf1RLUciw2P4RPfRPSJMUDtQqSYyyKaTfmHbbgXX6nu9wU4v7KlwR y+SVnpCnEpUJJCR0N7xxkdH5pSkQhRO5WFSU9BJzpq4u82OLU0tEKSoBEq4x6dBkSyNy 094g== X-Gm-Message-State: APjAAAU24F3O9k2XM4l9UyDdk0sbNmzOwDYwsO1QPEJe0oQKrKcypmW0 ZM8Q0PbzSo3hZyvclLaaMDzIdd8TiMV30oGhXESEH0GfR1sjfzujatWjgY892zJBQ5uTadesVti 8uQcQlq3cSpdWv8930g8= X-Received: by 2002:ab0:2408:: with SMTP id f8mr20161828uan.126.1579257842548; Fri, 17 Jan 2020 02:44:02 -0800 (PST) X-Google-Smtp-Source: APXvYqw1RGF7A/aBuT/0HoCdkkbP9d3DJbfz7LetfDyCmHrruQ/NR/wFnQbJ9/Pa44F2x9SWSjvbViFcrjF7vIsU3vg= X-Received: by 2002:ab0:2408:: with SMTP id f8mr20161654uan.126.1579257842127; Fri, 17 Jan 2020 02:44:02 -0800 (PST) MIME-Version: 1.0 References: <20200113130543.GC1645@bricha3-MOBL.ger.corp.intel.com> <20200113145823.GD1645@bricha3-MOBL.ger.corp.intel.com> <20200113161259.GE1645@bricha3-MOBL.ger.corp.intel.com> In-Reply-To: From: David Marchand Date: Fri, 17 Jan 2020 11:43:51 +0100 Message-ID: To: Jerin Jacob Cc: Bruce Richardson , Jerin Jacob Kollanukkaran , "dev@dpdk.org" , Thomas Monjalon , Ferruh Yigit , Andrew Rybchenko , Ajit Khaparde , Qi Zhang , Xiaolong Ye , Raslan Darawsheh , Maxime Coquelin , Tiwei Bie , Akhil Goyal , Luca Boccassi , Kevin Traynor , "maintainers@dpdk.org" , John McNamara , Marko Kovacevic , Ray Kinsella , Aaron Conole , Michael Santana , Harry van Haaren , Cristian Dumitrescu , Phil Yang , Joyce Kong , =?UTF-8?Q?Mattias_R=C3=B6nnblom?= , Jan Viktorin , Gavin Hu , David Christensen , Konstantin Ananyev , Anatoly Burakov , Harini Ramakrishnan , Omar Cardona , Anand Rawat , Olivier Matz , Gage Eads , Adrien Mazarguil , Nicolas Chautru , Declan Doherty , Fiona Trahe , Ashish Gupta , Erik Gabriel Carrillo , Abhinandan Gujjar , Hemant Agrawal , "Artem V. Andreev" , Nithin Kumar Dabilpuram , Vamsi Krishna Attunuru , Rosen Xu , Sachin Saxena , Stephen Hemminger , Chas Williams , "John W. Linville" , Prasun Kapoor , Marcin Wojtas , Michal Krawczyk , Guy Tzalik , Evgeny Schemeilin , Igor Chauskin , Ravi Kumar , Igor Russkikh , Pavel Belous , Shepard Siegel , Ed Czeck , John Miller , Somnath Kotur , Maciej Czekaj , Shijith Thotton , Srisivasubramanian Srinivasan , Rahul Lakkireddy , John Daley , Hyong Youb Kim , "Wei Hu (Xavier" , "Min Hu (Connor" , Yisen Zhuang , Ziyang Xuan , Xiaoyun Wang , Guoyang Zhou , Beilei Xing , Xiao Wang , Jingjing Wu , Wenzhuo Lu , Qiming Yang , Tomasz Duszynski , Liron Himi , Zyta Szpak , Kiran Kumar Kokkilagadda , Matan Azrad , Shahaf Shuler , Viacheslav Ovsiienko , "K. Y. Srinivasan" , Haiyang Zhang , Jan Remes , Heinrich Kuhn , Jan Gutter , Gagandeep Singh , Rasesh Mody , Shahed Shaikh , Yong Wang , Zhihong Wang , Steven Webster , Matt Peters , Keith Wiles , Tetsuya Mukawa , Jasvinder Singh , Jakub Grajciar , Ruifeng Wang , Anoob Joseph , Fan Zhang , Pablo de Lara , John Griffin , Deepak Kumar Jain , Michael Shamis , Nagadheeraj Rottela , Srikanth Jampala , Ankur Dwivedi , Jay Zhou , Lee Daly , Sunila Sahu , Nipun Gupta , Liang Ma , Peter Mccarthy , Tianfei zhang , Satha Koteswara Rao Kottidi , Xiaoyun Li , Bernard Iremonger , Vladimir Medvedkin , David Hunt , Reshma Pattan , Byron Marohn , Sameh Gobriel , Yipeng Wang , Honnappa Nagarahalli , Robert Sanford , Kevin Laatz , Maryam Tahhan , Ori Kam , Radu Nicolau , Tomasz Kantecki , Sunil Kumar Kori , Pavan Nikhilesh Bhagavatula , Kirill Rybalchenko , "Kadam, Pallavi" X-MC-Unique: djzsRohsN_ywNmFh4ujQbA-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [dpdk-dev] [RFC] DPDK Trace support X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Fri, Jan 17, 2020 at 10:52 AM Jerin Jacob wrote: > > > If someone needs more time to think through or any clarification is > > > required then please discuss. > > > > I did not find the time to look at this. > > Some quick questions: > > - is LTTng coming with out-of-tree kmod? making it hard to support in > > distributions? > > LTTng kernel tracing only needs kmod support. > For the userspace tracing at minium following libraries are required. > > a) LTTng-UST > b) LTTng-tools > c) liburcu > d) libpopt-dev > > Based on the https://lttng.org/docs/v2.11/#doc-installing-lttng > -------------------------- 8<---------------------------------- > Important:As of 22 October 2019, LTTng 2.11 is not available as > distribution packages, except for Arch Linux. > You can build LTTng 2.11 from source to install and use it. > -------------------------- >8---------------------------------- Would there be requirements on a specific version of LTTng? I can see RHEL 7 comes with version 2.4.1, RHEL 8 has 2.8.1. > > - I have been playing with perf those days to track live processes and > > gathering informations/stats at key point of a dpdk app without adding > > anything in the binary. What does LTTng provide that scripting around > > perf would not solve? > > Profiler and Tracer are two different things: Perf is a profiler. Are you sure you can draw such a line about perf? You can add dynamic tracepoints with context in a live process (perf probe/perf recordma), I used this to track where a variable was getting updated once for a given device in OVS (and getting the number of occurrences). I know there are limitations with perf (some static variables not being caught, can be tricky to trace inlines). Maybe LTTng is better at this since you put markers in your code. One thing of interest, I understand that LTTng does not require a context switch when tracing. That is an advantage over perf. -- David Marchand