1611820 - Minimize time spent loading modules in chromeutils.import when starting a first-time load

Status: RESOLVED FIXED

(GeckoView :: General, defect, P1)

Description

[Randell Jesup [:jesup] (needinfo me)]

When loading a URL in a new process in geckoview, a long time is spent importing modules and also running loadURIDelegate (and spinning the event loop waiting on the master process). See https://perfht.ml/2GsFALO

Comment 1

[Brendan Dahl [:bdahl]]

Randell,
What were your steps to produce this profile?

Locally on gecko view example, if I open a new tab I see GV import a number modules, but if I navigate to a new URL there aren't that many modules that are loaded. Also, on that profile there appears to be a good chunk of time spent loading devtools (which is not loaded regularly).

Comment 2

[Randell Jesup [:jesup] (needinfo me)]

Per comment 0, this is for loading into a new process in geckoview, which means a (re)start of Fenix, or a restart of the geckoview content process after it's been killed due to mem pressure.

It is loading devtools stuff; I don't know if that's due to the fact that we're capturing a profile remotely. If it isn't, then that's definitely something we'd want to avoid/defer loading.

Comment 3

[Brendan Dahl [:bdahl]]

Closing since the loadURIDelegate changes landed and the startup cache should be working more consistently to help with module load time now (bug 1624724).