Add funtrace

[oliver]

New function call tracer for C and C++ under x86/Linux: https://github.com/yosefk/funtrace

My understanding is that it creates files that can be analysed with https://profilerpedia.markhansen.co.nz/uis/viztracer-vizviewer/ .

[mhansen]

Thanks, yeah we should add funtrace. I’m not sure if the output format is perfetto, looked like perfetto from the screenshots I saw… need to dig more

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On Tue, 11 Feb 2025 at 22:42, Oliver Gerlich ***@***.***> wrote: New function call tracer for C and C++ under x86/Linux: https://github.com/yosefk/funtrace My understanding is that it creates files that can be analysed with https://profilerpedia.markhansen.co.nz/uis/viztracer-vizviewer/ . — Reply to this email directly, view it on GitHub <#32>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAZYOIUH3HZ7HRYKG4NZ6L2PHO2XAVCNFSM6AAAAABW42OWX6VHI2DSMVQWIX3LMV43ASLTON2WKOZSHA2DKMJTHEYDMMY> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[oliver]

Maybe @yosefk can give a hint about the output format that funtrace creates? Is it a file in "Trace Event Format" that can be opened with Perfetto, Chromium (about:tracing), Firefox Profiler etc.? Or can it only be opened with Viztracer?

(sorry, I did not even try funtrace myself yet, so can only speculate about the exact output format...)

[yosefk]

@mhansen @oliver funtrace (or rather its raw format decoder, funtrace2viz) produces a JSON file in the Chrome Trace Event Format that opens in http://ui.perfetto.dev; it has a "complete event" per function call, and it optionally collects ftrace data, which the JSON format supports straightforwardly (you just make the ftrace data - what you read from trace_pipe - the string value of some magic key.) The function call/return and ftrace timestamps use TSC as the time source and are converted to microseconds as required by the JSON format.

The JSON also has additional fields that vizviewer (a wrapper around viztracer's Perfetto fork) understands, mainly to add the functions' source code - this is done in its own keys which are ignored by stock Perfetto.

Will be happy to answer any other questions!