820422 - GC: Store buffered gray roots per-compartment

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jon Coppeard (:jonco)]

At the moment all the buffered gray roots are stored in the runtime.  This means that we have to iterate through all of them when marking a particular compartment.

A quick look at the number of roots showed that most compartments have few (if any) and some have very many, so I think it makes sense to split them up and store them by compartment.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Proposed fix

Comment 2

[Jon Coppeard (:jonco)]

Attachment: Proposed fix

Updated patch, fixed a couple of minor issues.

Comment 3

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Comment on attachment 691307 [details] [diff] [review]
Proposed fix

Review of attachment 691307 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/gc/RootMarking.cpp
@@ +798,5 @@
>      }
>  }
> +
> +void
> +js::gc::BufferGrayRoots(JSTracer *trc)

Can this take a GCMarker* instead of a JSTracer*?

::: js/src/jsgc.cpp
@@ +3556,5 @@
>      JS_ASSERT_IF(lastGC, !rt->gcSweepOnBackgroundThread);
>  
>      JS_ASSERT(rt->gcMarker.isDrained());
>      rt->gcMarker.stop();
> +    rt->gcMarker.resetBufferedGrayRoots();

Could GCMarker::stop call resetBufferedGrayRoots? Then this call and the one below wouldn't be needed.

Comment 4

[Jon Coppeard (:jonco)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/37b4c4b9d7d6

Comment 5

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/37b4c4b9d7d6