1368325 - js::gc::BarriersAreAllowedOnCurrentThread() shows up in performance profiles

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement)

Description

[Olli Pettay [:smaug][[e-mail]]]

js::gc::BarriersAreAllowedOnCurrentThread() is called in some very hot code paths, like inside GetWrapper.
Is there any way to avoid the tls lookup?

Comment 1

[Jan de Mooij [:jandem]]

I've noticed this too.

It's the MOZ_DIAGNOSTIC_ASSERT in ExposeGCThingToActiveJS so it does not affect release/beta, but it would help profiling to not have these perf differences between Nightly and beta.

Comment 2

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

We can remove this code now. We'll have to put it back if we ever revive bug 1308039, but that's fine.

Comment 3

[Jan de Mooij [:jandem]]

Attachment: Patch

This removes BarriersAreAllowedOnCurrentThread and related code.

Comment 4

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

Comment on attachment 8878025 [details] [diff] [review]
Patch

Review of attachment 8878025 [details] [diff] [review]:
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Thanks!

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/370bb186e98f
Remove JSContext::allowGCBarriers and related code as it's not used anywhere. r=billm

Comment 6

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

https://hg.mozilla.org/mozilla-central/rev/370bb186e98f