Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933459AbbHLCZZ (ORCPT ); Tue, 11 Aug 2015 22:25:25 -0400 Received: from mail-ob0-f172.google.com ([209.85.214.172]:36567 "EHLO mail-ob0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933064AbbHLCZY (ORCPT ); Tue, 11 Aug 2015 22:25:24 -0400 MIME-Version: 1.0 In-Reply-To: <7a0446748785048b03318202f2d6c99a@imap.eng.utah.edu> References: <7a0446748785048b03318202f2d6c99a@imap.eng.utah.edu> Date: Wed, 12 Aug 2015 10:25:23 +0800 Message-ID: Subject: Re: [ftrace] possible to implement user-space tracers? From: Kun Huang To: Scotty Bauer Cc: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2537 Lines: 80 Thank you for your help Scotty :) I'm reading it. On Wed, Aug 12, 2015 at 2:34 AM, Scotty Bauer wrote: > It is possible to trace from userland, Android does it. > > Essentially you need to write your data into > /sys/kernel/debug/tracing/trace_marker > > then read it out of /sys/kernel/debug/tracing/trace > > > If you care how the implementation works you can read it in > /kernel/tracing/trace.c > (http://lxr.free-electrons.com/source/kernel/trace/trace.c) search for > tracing_mark_fops and tracing_fops. > > > In Android here are the relevant files you will need to see how it's used in > userland: > Atrace (for reading data out + setting things up): > https://android.googlesource.com/platform/frameworks/native/+/master/cmds/atrace/atrace.cpp > https://android.googlesource.com/platform/external/chromium-trace/+/master > (host side setup of the device) > > trace-dev (for writing data in): > https://android.googlesource.com/platform/system/core/+/master/libcutils/trace-dev.c > > Once we have all the data we usually run it through trace-viewer, > (https://github.com/catapult-project/catapult) > > Cheers. > > >> On 2015-08-11 06:53, Kun Huang wrote: >>> >>> Hi ftrace developers >>> >>> I'm developing a huge python based programs and facing performance >>> issue everyday. I like the ftrace system and hope there could be a >>> tracer to trace&report my python codes. Is it possible or is it >> >> worthy >>> >>> to do this? >>> >>> --- >>> >>> Kun >>> -- >>> To unsubscribe from this list: send the line "unsubscribe >> >> linux-kernel" in >>> >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> [6] >>> >>> Please read the FAQ at http://www.tux.org/lkml/ [7] >> >> >> Links: >> ------ >> [1] http://lxr.free-electrons.com/source/kernel/trace/trace.c >> [2] >> >> https://android.googlesource.com/platform/frameworks/native/+/master/cmds/atrace/atrace.cpp >> [3] >> https://android.googlesource.com/platform/external/chromium-trace/+/master >> [4] >> >> https://android.googlesource.com/platform/system/core/+/master/libcutils/trace-dev.c >> [5] https://github.com/catapult-project/catapult >> [6] http://vger.kernel.org/majordomo-info.html >> [7] http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/