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

[Adrian Hunter]

On 29/06/23 09:26, Namhyung Kim wrote:
> Hi Anup,
> 
> On Wed, Jun 28, 2023 at 1:11 PM Anup Sharma <anupnewsmail@xxxxxxxxx> wrote:
>>
>> On Wed, Jun 14, 2023 at 01:17:52PM -0700, Ian Rogers wrote:
>>> On Wed, Jun 14, 2023 at 1:14 PM Anup Sharma <anupnewsmail@xxxxxxxxx> wrote:
>>>>
>>>> On Thu, Jun 08, 2023 at 06:23:49PM +0530, Anup Sharma wrote:
>>>> I wanted to take a moment to provide you with an update on the progress
>>>> of our Firefox Gecko converter work. While I must emphasize that the code
>>>> I'm sharing is not the final version, I wanted to share the advancements
>>>> I have made thus far.
>>>>
>>>> This script can generate a JSON format from the output of the "perf script" command.
>>>> I attempted to load this JSON file into profile.firefox.com, and although it
>>>> successfully loaded, the call tree are not visible. I'm certain this issue
>>>> is related to the format of the JSON file or if there is another underlying
>>>> cause. I will continue investigating to determine the cause of this problem.
>>>
>>> Great Anup, progress can be frustrating slow at first but it is a good
>>> milestone to be generating output and having firefox profiler consume
>>> it. You can open up the JavaScript console for the firefox profiler
>>> and it will give some debug output. This should hopefully help you
>>> make progress.
>>
>> This week I tried playing with perf-script-python, the first challenge was
>> figuring out how to parse the data coming from the process_events.
>> Understanding the structure and extracting the necessary information
>> proved to be more complex than anticipated. This required me to spend
>> a significant amount of time researching and experimenting with different
>> parsing techniques.
> 
> I'm not sure what kind of parsing you meant.  IIRC the sample data is
> in a dict and all the information should be available there.  Maybe we
> missed some new sample data types though.

Most data is there.  There are existing scripts in
tools/perf/scripts/python/ for reference.

There is also the dlfilter API:

https://perf.wiki.kernel.org/index.php/Latest_Manual_Page_of_perf-dlfilter.1

> 
>>
>> The second challenge revolved around the usage of event hooks provided with the perf script
>> python event handlers. I found myself deliberating between two approaches. The first
>> approach involved creating custom functions that would be called using the event
>> handlers. These functions would then save the data in an organized format within
>> globally created data structures. The alternative approach was to write the entire
>> logic inside the event handlers themselves.
>>
>> Additionally, I contemplated whether it would be more suitable to handle the creation of
>> a Gecko format for JSON and the profile format within the same script or to separate
>> them into different scripts.
>>
>> I will discuss this points during tomorrow's office hour.
>>
>> However, I have gained a deeper understanding of the problem at hand and will use this
>> knowledge to make more informed decisions and progress more effectively in the coming weeks.
> 
> Sounds like you did a good amount of research on how perf script
> works.  We can talk about the details in the meeting.
> 
> Thanks,
> Namhyung