[mstange]

Main | Deploy preview

I've been using this script to make profiles of Firefox startup on Android, with sample data from simpleperf and marker data from the Gecko profiler.

I was using the following org.mozilla.fenix-geckoview-config.yaml:

env:
  PERF_SPEW_DIR: /storage/emulated/0/Android/data/org.mozilla.fenix/files
  IONPERF: func
  JIT_OPTION_emitInterpreterEntryTrampoline: true
  JIT_OPTION_enableICFramePointers: true
  JIT_OPTION_onlyInlineSelfHosted: true

  MOZ_PROFILER_STARTUP: 1
  MOZ_PROFILER_STARTUP_NO_BASE: 1 # bug 1955125
  MOZ_PROFILER_STARTUP_INTERVAL: 500
  MOZ_PROFILER_STARTUP_FEATURES: nostacksampling,nomarkerstacks,screenshots,ipcmessages,java,cpu,markersallthreads
  MOZ_PROFILER_STARTUP_FILTERS: GeckoMain,Compositor,Renderer,IPDL Background,*

Example profiles to merge: https://share.firefox.dev/4ssKZZq and https://share.firefox.dev/48gWwSb

You can run it with yarn build-node-tools && node ./node-tools-dist/profiler-edit.js -i 'https://storage.googleapis.com/profile-store/ycbv8644eb0e11n62hgh04yya7xgamhq2qgd94r' -o ~/Downloads/merged.json.gz --merge-markers-from 'https://storage.googleapis.com/profile-store/ag9r7sm5h7zgxphw8werwqs22gdf7kt50q0dqf0' --only-keep-processes-with-name-prefix org.mozilla.fenix

Loading profile from URL https://storage.googleapis.com/profile-store/ycbv8644eb0e11n62hgh04yya7xgamhq2qgd94r
Kept 418 of 2540 threads in processes whose name starts with "org.mozilla.fenix".
Loading profile from URL https://storage.googleapis.com/profile-store/ag9r7sm5h7zgxphw8werwqs22gdf7kt50q0dqf0
Merged the markers of 178 threads, aligning the profiles with startTimeAsClockMonotonicNanosecondsSinceBoot.
Saving profile to /Users/mstange/Downloads/merged.json.gz
Finished.

This gives https://share.firefox.dev/4z2OoQx .

[codecov]

Codecov Report

❌ Patch coverage is 78.12500% with 28 lines in your changes missing coverage. Please review.
✅ Project coverage is 84.78%. Comparing base (7269a79) to head (9db4c81).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node-tools/profiler-edit.ts	41.17%	20 Missing ⚠️
src/profile-logic/merge-markers.ts	91.48%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5448      +/-   ##
==========================================
- Coverage   84.78%   84.78%   -0.01%     
==========================================
  Files         358      359       +1     
  Lines       38946    39063     +117     
  Branches    10917    11066     +149     
==========================================
+ Hits        33022    33120      +98     
- Misses       5488     5507      +19     
  Partials      436      436              

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[fqueze]

Is this specific to android? I could be tempted to merge a samply profile with a resource usage profile.

[mstange]

The part that's specific to Android / Linux is the use of startTimeAsClockMonotonicNanosecondsSinceBoot to align the timestamps in the two profiles.

Also, the markers from the "samples" profile are discarded. You are probably interested in keeping markers from both profiles, which will be more complicated because you'll also have to merge the schemas.

[fqueze]

You are probably interested in keeping markers from both profiles, which will be more complicated because you'll also have to merge the schemas.

If we added more useful markers to samply profiles, yes. Currently all the markers I see in these profiles are mmap markers that don't tell me much.

[mstange]

I've ported the script functionality to the profiler-edit script. I'd like to use this in CI to create better profiles for the newssite-applink-startup test.

https://bugzilla.mozilla.org/show_bug.cgi?id=2085919