1613430 - Reinstate early dll prefetching on Nightly

Status: RESOLVED FIXED

(Core :: XPCOM, task)

Description

[Alex Thayer [:alexical] (she/her)]

The changes from 1565902 fixed a peculiar performance problem that a seemingly very small number of users hit, but it also regressed some of our other startup metrics. It seems that it is still best to simply go back to prefetching all of xul (and the other libraries in dependentlibs.list) in Nightly (which will match Release).

Comment 1

[Alex Thayer [:alexical] (she/her)]

(This wasn't clear from the initial comment - the issue in bug 1565902 seems to have been resolved for the user by a Windows update. The problem being at root a Windows bug, or a driver bug or something generally out of our direct control, aligns with our evidence as well.)

Comment 2

[Alex Thayer [:alexical] (she/her)]

Attachment: Bug 1613430 - Go back to LibLoadingStrategy::ReadAhead on Nightly r?glandium

The original issue in bug 1565902 which prompted this investigation
seems to have gone away with a Windows OS update. We saw mixed results
in telemetry over this anyway, and no clear and obvious path for
getting the benefits without the drawbacks, so removing this seems
to be the best solution right now.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f0cb6e48329b
Go back to LibLoadingStrategy::ReadAhead on Nightly r=glandium

Comment 4

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/f0cb6e48329b