1958201 - Increase the child timeout to something more sensible

Status: RESOLVED FIXED

(Core :: Gecko Profiler, enhancement)

Description

[Julien Wajsberg [:julienw]]

When gathering the profile chunks from processes, there's a timeout to avoid infinite waiting.
The default (and minimum) is 1 second as written in [1] but it can also be changed by a pref in [2].
https://searchfox.org/mozilla-central/rev/7014a821bb4689deb04f647a153a6db10e580a00/modules/libpref/init/all.js#650

We got several reports of losing subprocesses data, especially the ones that were interesting. There's the added issue that the speed will depend on the speed of the computer.

Therefore I'd suggest to increase the timeout to 15 seconds. This is still small enough that if there's a real issue the user won't wait too long, but large enough to let the subprocess generate the json.

[1] https://searchfox.org/mozilla-central/rev/7014a821bb4689deb04f647a153a6db10e580a00/tools/profiler/gecko/nsProfiler.cpp#1280-1283
[2] https://searchfox.org/mozilla-central/rev/7014a821bb4689deb04f647a153a6db10e580a00/modules/libpref/init/all.js#650

Comment 1

[Julien Wajsberg [:julienw]]

Attachment: Bug 1958201 - [profiler] Increase the child gathering profile timeout to 15 seconds r=canaltinova

When gathering the profile chunks from processes, there's a timeout to
avoid infinite waiting. The default (and minimum) is 1 second but this
can also be specified by a pref.

We got several reports of losing subprocesses data, especially the ones
that were interesting. There's the added issue that the speed will
depend on the speed of the computer.

Therefore this patch changes the pref to increase the timeout to 15
seconds. This is still small enough that if there's a real issue the
user won't wait too long, but large enough to let the subprocess
generate the json.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/143927aa36a1
[profiler] Increase the child gathering profile timeout to 15 seconds r=canaltinova

Comment 3

[Cristina Horotan [:chorotan]]

Backed out for causing bc failures at browser_test_profile_slow_capture.js

Backout link

Push with failures

Failure log

Comment 4

[Julien Wajsberg [:julienw]]

Thanks, I updated the related code.

Some try builds:
https://treeherder.mozilla.org/jobs?repo=try&revision=314fdf62eaa882210980678aea94bcf61c3fd465
https://treeherder.mozilla.org/jobs?repo=try&revision=7a0ace41c9e8f6bc9b63e914a8ef19230aaa8070

Comment 5

[Julien Wajsberg [:julienw]]

A new one after Nazim's suggested fix: https://treeherder.mozilla.org/jobs?repo=try&revision=e254d30be765f164819c6ed2f9e141a03564b8ef

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d8d3be046eea
[profiler] Increase the child gathering profile timeout to 15 seconds r=canaltinova,profiler-reviewers

Comment 7

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/d8d3be046eea