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 0675CA04F0; Mon, 13 Jan 2020 16:13:20 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 60D951C29C; Mon, 13 Jan 2020 16:13:20 +0100 (CET) Received: from mail-io1-f67.google.com (mail-io1-f67.google.com [209.85.166.67]) by dpdk.org (Postfix) with ESMTP id C93391C22E; Mon, 13 Jan 2020 16:13:18 +0100 (CET) Received: by mail-io1-f67.google.com with SMTP id b10so10115723iof.11; Mon, 13 Jan 2020 07:13:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=2Ji6eraVHR9oSLwGL1DE1vhzG4usM/RmmzzsB131Pqo=; b=MFMJFUMsqkJ0KvaPXkF8Mus/q1Qz6C1GL9iy67uL4HLn7BEgopSLZhbNNaw6qCCxIv 9uXEWCm/81gDqN1pCQ9CjVd0rB+KXWMzRR8KKch7AjyyoAk+KiAGtSEKlodmAlGKl+b6 duC2IksygO6TnjMY6023jVAeGC4jhf2tFreQ/KaqLwb5lJ8EceEEvaUlueHmDIhlymz0 ybQOtncF9P6oeiQW8hb3hQQ+PB8uIH3wn2I+d6jbTgU0bbRJ0i8Um3XHyBmjfXLRe3Ml CfsmC0yueya7Qb54FRuUDBbsc1IdkXsrhtMmFbkPgn6nV0K+OBAE8Qe2pkixvQDmNdAg AgUA== 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=2Ji6eraVHR9oSLwGL1DE1vhzG4usM/RmmzzsB131Pqo=; b=a9GINk0FS6Nu0cEN+vDH9e5xdyXPwj6KHbdSluKHnFdq+Hv2SrFfXkpFztm9Dc5A8H B7LZRuXkkHq65Gg5LRHiar4ptI9pCpxB2P0k5YDdYxu91quoVe4GZyjLbMZWGq1y/CcQ V8hkYmyEoKyXsIVD5Y0q90+CWn//Cz3DqoW6c9BuCK55oeVFh04rc0Vx/Aw3n+4l1f4M nxMjd2qGs08xXO0bqZbcSGhtFlGTifggneZnM6d1LhXOlMLXWNyo15Oy5LFKphB+LZNu fVNL1LdRWABGQTN49yIvRayRBnoUM9C/e4RBd/Z1KnleqcsmUfY8n3NMMYCcBu/4pXwK hq5g== X-Gm-Message-State: APjAAAWoAWNkfkwDsFvQe/2KWHyaRQIarZkwhGBu1qN7riOG/ZBTCKTY xnB+GOKhQvo5+PD34WjyoA6uOhPrH1hJ+BDgz2w= X-Google-Smtp-Source: APXvYqzoIa0F3/FdoMGpyktIUrE32R25hEVjlkToJuUO6rzl5fTb16QZ2DmthBSDT4ogO4eCtlD032DOz7UxpYaRNe0= X-Received: by 2002:a02:b808:: with SMTP id o8mr15192814jam.104.1578928397893; Mon, 13 Jan 2020 07:13:17 -0800 (PST) MIME-Version: 1.0 References: <20200113130543.GC1645@bricha3-MOBL.ger.corp.intel.com> <20200113145823.GD1645@bricha3-MOBL.ger.corp.intel.com> In-Reply-To: <20200113145823.GD1645@bricha3-MOBL.ger.corp.intel.com> From: Jerin Jacob Date: Mon, 13 Jan 2020 20:43:01 +0530 Message-ID: To: Bruce Richardson Cc: Jerin Jacob Kollanukkaran , "dev@dpdk.org" , Thomas Monjalon , David Marchand , 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 , Ranjit Menon , Olivier Matz , Gage Eads , Adrien Mazarguil , Nicolas Chautru , Declan Doherty , Fiona Trahe , Ashish Gupta , Erik Gabriel Carrillo , Abhinandan Gujjar , Shreyansh Jain , 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 , Gaetan Rivet , 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" Content-Type: text/plain; charset="UTF-8" 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 Mon, Jan 13, 2020 at 8:28 PM Bruce Richardson wrote: > > On Mon, Jan 13, 2020 at 08:16:07PM +0530, Jerin Jacob wrote: > > On Mon, Jan 13, 2020 at 6:36 PM Bruce Richardson > > wrote: > > > > > > > > > > So, Probably it good to have native CTF emitter in DPDK and reuse all > > > > open-source trace viewer(babeltrace and TraceCompass) and format(CTF) infrastructure. > > > > I think, it would be best of both world. > > > > > > > > Any thoughts on this subject? Based on the community feedback, I can work on the patch for v20.05. > > > > > > Forgive my ignorance of LTTng, but is there the concept of > > > enabling/disabling the trace points? If so, the overhead you refer to, that > > > is presumably with the trace enabled? > > > > Yes this is when trace is enabled. If the trace is disabled then it > > will be the only a handful of cycles. > > > Two follow-on questions: > 1. Is the trace enable/disable dynamic at runtime? Yes. See the requirement section. > 2. Have you investigated how low the "handful of cycles" actually is? Yes. it is around 1 to 3 cycles based on the arch. it boils down to mostly a branch hit/miss on a memory location embedded in a C macro. > While I think it is important to get the cost of tracing right down to make > it useful, the cost of tracing when it is not being used is even more > critical IMHO. Yes. > > /Bruce