1156552 - Out-of-line BaseShape tracing

Status: RESOLVED FIXED

(Core :: JavaScript: GC, defect)

Description

[Terrence Cole [:terrence]]

Attachment: 10.2_outofline_baseshape_tracing-v0.diff

BaseShapes are the 3rd least frequently called marker, and they don't recurse, so there is no need to have 2 copies for performance.

Comment 1

[Steve Fink [:sfink] [:s:]]

Comment on attachment 8595026 [details] [diff] [review]
10.2_outofline_baseshape_tracing-v0.diff

Review of attachment 8595026 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/gc/Marking.cpp
@@ -1064,5 @@
> -GCMarker::eagerlyMarkChildren(BaseShape* base)
> -{
> -    base->assertConsistency();
> -
> -    base->compartment()->mark();

What was this for, and why is it no longer necessary?

Comment 2

[Terrence Cole [:terrence]]

Good catch! I've no idea what it's for, but other types seem to have it as well. In particular, JSScript::traceChildren has an |if (trc->isGCMarker()) compartment()->mark()|, so I've added that pattern here as well.

Comment 3

[Jon Coppeard (:jonco)]

(In reply to Terrence Cole [:terrence] from comment #2)
Looks like it's for working out which compartments in a zone are still live in GCRuntime::sweepZones() and Zone::sweepCompartments().

Comment 4

[Terrence Cole [:terrence]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=9d4c64043ab2

Comment 5

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/a7ad947cdcb7

Comment 6

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/a7ad947cdcb7