1735500 - When we do not have the initial URI a page is loading, default the browser to the PRIVILEGEDABOUT_REMOTE_TYPE

Status: RESOLVED FIXED

(Firefox :: Tabbed Browser, task)

Description

[Mark Banner (:standard8)]

In looking at landing bug 1649599, we saw some performance regressions in the startup_about_home_* tests.

Investigation showed that due to the performance improvements for sessionstore, it was being initialised earlier. As a result, gBrowserInit.uriToLoadPromise would return a promise rather than a URI, which means this piece of code is triggered. The result is that it causes the first browser to be loaded as a web content process, and we then have to later change to the privileged about process.

Changing that to load the browser as PRIVILEGEDABOUT_REMOTE_TYPE does not appear to hurt session restore performance (the improvements remain), but also fixes the startup_about_home_* regressions. This makes sense as it is restoring the status-quo.

Whilst we could await on the promise, that would mean that gBrowser.selectedBrowser might not always exist - which would potentially break a lot of code.

Comment 1

[Mark Banner (:standard8)]

Attachment: Bug 1735500 - When we do not have the initial URI the first browser in a window is loading, default the browser to the PRIVILEGEDABOUT_REMOTE_TYPE. r?gijs!

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8f569a8aacf0
When we do not have the initial URI the first browser in a window is loading, default the browser to the PRIVILEGEDABOUT_REMOTE_TYPE. r=Gijs

Comment 3

[Cosmin Sabou [:CosminS]]

Backed for causing both Bug 1735649 and Bug 1735650.

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&selectedTaskRun=E3EC0OCuQCqlxqGeOxxH3w.0&resultStatus=testfailed%2Cbusted%2Cexception%2Cusercancel&revision=c7b8bd49a7415ef37864df2d2a30229a337dee4f

Failure log:

• https://treeherder.mozilla.org/logviewer?job_id=354691081&repo=autoland
• https://treeherder.mozilla.org/logviewer?job_id=354688323&repo=autoland

Backout link: https://hg.mozilla.org/integration/autoland/rev/2d35f63eeba72fe7c827c992b7b0ca8f21d57d08

Comment 4

[Mark Banner (:standard8)]

We've fixed a Marionette test issue, but we can't reproduce the main failure on try server:

https://treeherder.mozilla.org/jobs?repo=try&revision=3d33640229b5066b107d53749e343212c06c758a

We're going to try landing again and see what happens. It could have been a conflict with another patch that had landed or something like that.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/16d787b72947
When we do not have the initial URI the first browser in a window is loading, default the browser to the PRIVILEGEDABOUT_REMOTE_TYPE. r=Gijs

Comment 6

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/16d787b72947

Comment 7

[Acasandrei Beatrice (needinfo me)]

== Change summary for alert #31952 (as of Tue, 19 Oct 2021 06:06:21 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
7%	JS	windows10-64-2004-shippable-qr	tp6	261,403,577.71 -> 242,255,369.97
6%	Explicit Memory	windows10-64-2004-shippable-qr	tp6	672,551,393.30 -> 631,045,730.28
6%	Resident Memory	windows10-64-2004-shippable-qr	tp6	897,387,752.06 -> 847,368,710.55
5%	Resident Memory	windows10-64-2004-shippable-qr	tp6	903,676,210.53 -> 856,928,896.44

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=31952