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 F0418A051A; Fri, 17 Jan 2020 09:05:05 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 5B3831D16C; Fri, 17 Jan 2020 09:05:05 +0100 (CET) Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by dpdk.org (Postfix) with ESMTP id DC7791D16B for ; Fri, 17 Jan 2020 09:05:03 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579248303; 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=92H6A+FhE7wEFhptELSnxic50iLdJ1bJpF0BLxFmMIs=; b=YFiKRlrUTjaJVVE3rJUfsHUVEaPxa5XMfZ7QrD1aWJB42R6iR1fneptgWkJybO+TXA2piE 60FxlOb0digIvqNnHFQeahUtwpWteYIMLPV2U7tkK7m0/w4nmcdhitIwAL8PIj2bRpaNHS 2oe3mpKP2D5Hq/C+/94dR+b40eHAcYo= Received: from mail-ua1-f70.google.com (mail-ua1-f70.google.com [209.85.222.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-248-ntBG05O_NvqRo77Hh18I4Q-1; Fri, 17 Jan 2020 03:05:01 -0500 Received: by mail-ua1-f70.google.com with SMTP id i21so3750423uac.10 for ; Fri, 17 Jan 2020 00:05:01 -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=OuMIKFaQ0xLqFSQWJT5h5FEJbxNV/Ym2KXUIHIy42mI=; b=tC85Y2cXykX1WDdTchYb6HqCmdW/tIU1wP+MvvTo62Eozq5tb8qNzNqgS7oPVDivnd mm5fEWJFJ2Ty9oh0jMEv6yntV+nsHqK5tK32wcYPUKVPwmTTyU5FjLB3X77lhWDyY/82 NiXlgNtiyOUaYO/sN3SQurEc1jQ29yLbxoG1704aQI1b9t3afqO8B3zolS6ktb5ojkTX Qx0/yE4bdT8ZgkXm5Dfwj3r9wsuOGROfrqs6CvzJIdfRfYMZhFarF0R50kFs1mbsb3MP Vdksrqk8/WMYpDqO7Nu4o4Anzd9VvoP1eB7F1ZN360GDn75dCysQTV9346b/y+szDNW5 uycg== X-Gm-Message-State: APjAAAX463HGfQINYo2op+eW7J8Q/Ie4uuUj3Eesg6Vo9OaSGQf+I2H6 gmELH23G+QPi8rdcU5lHkIE7w77iazlr3Y0TpmeSZjJ6tv6v3j7VjY/e/9X4/DJnQs84BZ5SyRW HifiFQB19bkg6yyDt7mQ= X-Received: by 2002:a67:e342:: with SMTP id s2mr4020829vsm.198.1579248301013; Fri, 17 Jan 2020 00:05:01 -0800 (PST) X-Google-Smtp-Source: APXvYqxhVXQo6rNf6PHhljSjB/XOzta6ATxZE1Xulv4LAwy6iaEpRrkuo3peQuHwYbzU+bme6hq3T9pNsUfaFwCAfk4= X-Received: by 2002:a67:e342:: with SMTP id s2mr4020803vsm.198.1579248300568; Fri, 17 Jan 2020 00:05:00 -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 09:04:49 +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: ntBG05O_NvqRo77Hh18I4Q-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 5:41 AM Jerin Jacob wrote: > > > > > > > > > > > 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 i= s? > > > > > > 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. > > > > > That seems impressively low, which is great news! > > Does anyone have an objection to have > 1) Use CTF as trace format to reuse the opensource tracing tools and > compatibility wth LTTng > https://diamon.org/ctf/ > 2) Have native DPDK CTF trace emitter for better performance for DPDK > fast path tracing and Non-Linux support. > > I would like to avoid the situation where once code gets completed and > then starts our basic discussion > on the design decisions. > > 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? - 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? --=20 David Marchand