891436 - GC: Skip heap walk for profilingScripts during minor GC

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Terrence Cole [:terrence]]

Attachment: v0

This is making TBPL orange at the moment. The problem is that, as we discovered in bug 889682, walking the heap inside of a minor GC is dangerous.  I'm very surprised that we did not hit this earlier.

Comment 1

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

Comment on attachment 772727 [details] [diff] [review]
v0

Review of attachment 772727 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/gc/RootMarking.cpp
@@ +712,5 @@
>              zone->markTypes(trc);
>          }
>  
>          /* Do not discard scripts with counts while profiling. */
> +        if (!rt->isHeapMinorCollecting() && rt->profilingScripts) {

Could you switch the order of these conditions? The first one is more relevant.

Comment 2

[Terrence Cole [:terrence]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/a65599fc1dd4

Comment 3

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/a65599fc1dd4