1846270 - GC profile background work time double counts parallel marking time

Status: RESOLVED FIXED

(Core :: JavaScript: GC, defect, P5)

Description

[Jon Coppeard (:jonco)]

The 'bgwrk' column of profile information produced when using JS_GC_PROFILE double counts time spent parallel marking.

This is because it sums all parallel phase times, and parallel marking records its total time separately from time spend marking and waiting.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Bug 1846270 - Split times recorded for parallel marking as these will be summed later r?sfink

Total background time sums all phases so this currently double counts time from
parallel marking. The patch stop recording the total time separately and
instead records its componenets.

Depends on D184939

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/fd510d9d3f04
Split times recorded for parallel marking as these will be summed later r=sfink

Comment 3

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/fd510d9d3f04

Comment 4

[Jon Coppeard (:jonco)]

Attachment: Bug 1846270 - Fix parallel marking utilization telemetry broken by previous patch in this bug r?sfink

My previous patch changed the way |parallelRunTime| by adding waiting time
where it was previously subtracted. The utilization telemetry is meant to show
the fraction of time the helper threads spent running so waiting time should
not be included.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5616c5fbcec0
Fix parallel marking utilization telemetry broken by previous patch in this bug r=sfink

Comment 6

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/5616c5fbcec0