1978751 - Full (all-zones) GCs are triggered for allocation triggers

Status: RESOLVED FIXED

(Core :: Cycle Collector, defect)

Description

[Jon Coppeard (:jonco)]

When the JS engine finds a zone's memory thresholds have been exceeded it triggers a GC for that single zone. However the cycle collector will add in all other zones if it didn't have any zones it was going to schedule, which is probably the case a lot of the time. This means we do full GCs more often than we need to.

Fixing this should increase the proportion of zone GCs and reduce the amount of GC work.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Bug 1978751 - Stop collecting all zones for internally triggered GCs r?mccr8

If a GC has been triggered internally by the JS engine the cycle collector will
likely not have any zones waiting. The patch stops a full GC being triggered in
this case.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/c377b2cc133a
https://hg.mozilla.org/integration/autoland/rev/a67ee403b816
Stop collecting all zones for internally triggered GCs r=mccr8

Comment 3

[agoloman]

https://hg.mozilla.org/mozilla-central/rev/a67ee403b816

Comment 4

[Mayank Bansal]

14% imrpovement on Ares6-Basic_firstiteration