1788073 - Count marked cells when finalizing rather then when marking

Status: RESOLVED FIXED

(Core :: JavaScript: GC, task, P3)

Description

[Jon Coppeard (:jonco)]

We report telemetry on the marking rate, calculated from the number of cells marked and the time we spent in the marking phase.

The count of marked cells is calculated when marking but this is unnecessary because we already count the number of cells marked when we finalize arenas (and this mainly happens off thread).

This (slightly) simplifies marking.

There is a small discrepancy because this doesn't count atoms that are marked when we are not collecting the atoms zone, so this may affect the reported mark rate a little. I don't think it's important that this is accurate though, it's there to tell us if we regress marking preformance.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Bug 1788073 - Compute mark count during sweeping r?sfink

We already count the number of marked cells when finalizing arenas so use that
instead of counting in the mark phase as well.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/79073b1a3af3
Compute mark count during sweeping r=sfink

Comment 3

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/79073b1a3af3