Re: [RFC] Adding Support for Firefox's Gecko Profile Format

[Ian Rogers]

On Thu, May 25, 2023 at 1:53 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> Hi Anup,
>
> On Wed, May 24, 2023 at 12:25 PM Anup Sharma <anupnewsmail@xxxxxxxxx> 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 tool 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 Firefox 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=address' 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 least.
>
> >
> > I have one question regarding the installation process. Typically, I navigate to the perf directory,
> > run 'make', and then cp 'perf' to '/usr/bin'. However, I noticed that by default, perf is installed in
> > the '~/bin/perf' directory. Could someone please clarify why this is the 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=1" to enable BPF.
>
> Thanks,
> Namhyung

I quite often test with address sanitizer, I do this by passing to make:
DEBUG=1 EXTRA_CFLAGS="-O0 -g -fno-omit-frame- pointer
-fsanitize=address" NO_LIBTRACEEVENT=1

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/perf/Makefile.perf?h=perf-tools-next

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

Perhaps you can suggest improvements :-)

Thanks,
Ian

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