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From:   Ian Rogers <irogers@google.com>
Date:   Fri, 26 May 2023 08:17:44 -0700
Message-ID: <CAP-5=fVekEnC1s=xUG-jFeL20qM=EPNkPO8aw8bcg4cVM=m5wg@mail.gmail.com>
Subject: Re: [RFC] Adding Support for Firefox's Gecko Profile Format
To:     Namhyung Kim <namhyung@kernel.org>
Cc:     Anup Sharma <anupnewsmail@gmail.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
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On Thu, May 25, 2023 at 1:53=E2=80=AFPM Namhyung Kim <namhyung@kernel.org> =
wrote:
>
> Hi Anup,
>
> On Wed, May 24, 2023 at 12:25=E2=80=AFPM Anup Sharma <anupnewsmail@gmail.=
com> wrote:
> >
> > Hello everyone,
> >
> > I'm happy to share that I'll be working on adding support for Firefox's=
 Gecko profile format.
> > This format is utilized by the Firefox profiler, which is a powerful to=
ol for performance analysis
> > and debugging. By enhancing the perf data command to generate perf.data=
 files in the Gecko
> > profile format, it will allow us to leverage the capabilities of the Fi=
refox profiler for visualizing
> > and analyzing the performance data.
> >
> > As a starter task, I have created a test for testing the perf data JSON=
 converter command.
> > I'm also looking for a few more starter tasks related to this project. =
I would greatly appreciate
> > your advice and guidance.
> >
> > In my effort to identify any existing bugs, I have enabled flags like '=
fsanitize=3Daddress' to detect
> > potential issues but have not found any :). Additionally, I am running =
perf data commands to ensure
> > that all use cases are handled properly.
>
> Great, good to know it works well with asan for the basic use cases at le=
ast.
>
> >
> > I have one question regarding the installation process. Typically, I na=
vigate to the perf directory,
> > run 'make', and then cp 'perf' to '/usr/bin'. However, I noticed that b=
y default, perf is installed in
> > the '~/bin/perf' directory. Could someone please clarify why this is th=
e case? Furthermore, I would
> > like to know how all of you compile the perf tree.
>
> I guess $HOME is the default prefix unless you set it to other, then
> make install will put
> the binary there.  You can make sure if your PATH contains the ~/bin and =
use it.
>
> But it's also possible you can run the perf without installing.  I
> have a symlink in
> my tmp directory to point to the recent build of the binary and use it
> always. :)
> To build, you can either 'cd tools/perf; make' or 'make -C tools/perf'
> in the top
> level linux source tree.  I also pass "BUILD_BPF_SKEL=3D1" to enable BPF.
>
> Thanks,
> Namhyung

I quite often test with address sanitizer, I do this by passing to make:
DEBUG=3D1 EXTRA_CFLAGS=3D"-O0 -g -fno-omit-frame- pointer
-fsanitize=3Daddress" NO_LIBTRACEEVENT=3D1

The libtraceevent exclusion is to avoid false address sanitizer
warnings in libtraceevent (it wasn't compiled with address sanitizer).
The other flags are to make the code easier to debug. A good place to
start for a description of the build flags is Makefile.perf:
https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/p=
erf/Makefile.perf?h=3Dperf-tools-next

There's also some description here:
https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/p=
erf/Documentation/Build.txt?h=3Dperf-tools-next

Perhaps you can suggest improvements :-)

Thanks,
Ian

> >
> > Thank you for your support and I'm looking forward to collaborating wit=
h you on this project!