1386407 - Disable javascript.options.asyncstack when running AWSY tests

Status: RESOLVED FIXED

(Testing :: AWSY, enhancement)

Description

[Eric Rahm [:erahm]]

`javascript.options.asyncstack` [1] is used for debugging promises in devtools, it's disabled by default in beta and release. We should also disable it during testing as it is causing memory regressions as more code switches to native promises.

[1] http://searchfox.org/mozilla-central/rev/bbc1c59e460a27b20929b56489e2e55438de81fa/modules/libpref/init/all.js#1433

Comment 1

[Eric Rahm [:erahm]]

Attachment: Part 1: Disable javascript.options.asyncstack during AWSY testing

This avoids the extra memory overhead from providing debug information for
promises. The `javascript.options.asyncstack` pref is disabled by default in
release and beta so this better mirrors what users will see.

MozReview-Commit-ID: 5H8Kc08hjq9

Comment 2

[Eric Rahm [:erahm]]

Attachment: Part 2: Use prefs.json when testing locally

We specify '--preferences' in `awsy_script.py`, but weren't doing so for
local testing. This uses 'conf/prefs.json' by default, but lets the user
override that by specifying '--preferences'.

MozReview-Commit-ID: 5j7a1LA4e8a

Comment 3

[Eric Rahm [:erahm]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/719904f702d33651e9dcfb5d2a998766cfb70095
Bug 1386407 - Part 1: Disable javascript.options.asyncstack during AWSY testing. r=bc

https://hg.mozilla.org/integration/mozilla-inbound/rev/f4bb7fcea63e546e350bbffcc8379fb7ee333f51
Bug 1386407 - Part 2: Use prefs.json when testing locally. r=bc

Comment 4

[Joel Maher ( :jmaher ) (UTC -8)]

== Change summary for alert #8488 (as of August 01 2017 22:55 UTC) ==

Improvements:

  2%  JS summary linux64 opt      115,106,387.70 -> 112,477,988.47
  2%  JS summary windows7-32 pgo  94,413,368.73 -> 92,401,944.59
  2%  JS summary windows10-64 pgo 126,978,628.95 -> 124,293,846.65

For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=8488

Comment 5

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/719904f702d3
https://hg.mozilla.org/mozilla-central/rev/f4bb7fcea63e