1575453 - Optional AUTO_BASE_PROFILER_STATS to gather dev-specific profiler overhead

Status: RESOLVED FIXED

(Core :: Gecko Profiler, task, P2)

Description

[Gerald Squelart (he/him)]

While working on changing the way we store markers, I want to gather some overheads before and after, to compare profiler performance.

Note that this is intended only for internal developer consumption, so it will be controlled by a #define and output results in printfs, and will be off by default. I'll enable it locally and in some tries.

Comment 1

[Gerald Squelart (he/him)]

Attachment: Bug 1575453 - AUTO_PROFILER_STATS (off by default) - r?gregtatum

AUTO_BASE_PROFILER_STATS(name) can be used to time a {block}.
Statistics are gathered in a function-static variable, and printf'd when the
program ends.

Depends on D42824

Comment 2

[Gerald Squelart (he/him)]

Attachment: Bug 1575453 - Collect stats for sampling, and markers (add, collect, expire) - r?gregtatum

Use AUTO_BASE_PROFILER_STATS in both profilers, in:

• SamplerThread::Run() calling DoPeriodicSample()
• racy_profiler_add_marker
• ProfileBuffer::DeleteExpiredStoredMarkers()

This should cover all areas affected by the upcoming changes to the
ProfileBuffer storage, and how markers are stored.

Depends on D42825

Comment 3

[Gerald Squelart (he/him)]

Try with stats disabled by default:
https://treeherder.mozilla.org/#/jobs?repo=try&selectedJob=262665625&revision=0e3fec66a99017dac9ca9507c5ce32b1b2c77014

Try with stats enabled:
https://treeherder.mozilla.org/#/jobs?repo=try&selectedJob=262665625&revision=12822c74c5203a2b5066c4e481e81144a82ebeed
(Look for "profiler stats" in 'Cpp' and 'Gtest' logs.)

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e8848c8fdfdb
AUTO_PROFILER_STATS (off by default) - r=gregtatum
https://hg.mozilla.org/integration/autoland/rev/36da91720ede
Collect stats for sampling, and markers (add, collect, expire) - r=gregtatum

Comment 5

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/e8848c8fdfdb
https://hg.mozilla.org/mozilla-central/rev/36da91720ede