964214 - GenerationalGC: Some minor improvements to minor collection

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Comment 1

[Jon Coppeard (:jonco)]

Attachment: dont-wait-for-bg

Currently we wait for background sweeping to finish before we start a minor GC.  Since we don't alter the marks bits, I don't think this is necessary.

Comment 2

[Jon Coppeard (:jonco)]

Attachment: dont-recompact

If a store buffer is found to be about to overflow when we try to put a new entry we compact it, and if that fails to free any space, we trigger a minor GC.  That minor GC will unnecessarily try to compact the buffer again.

Compacting a full store buffer takes ~300 uS on my machine.

Comment 3

[Terrence Cole [:terrence]]

Comment on attachment 8365878 [details] [diff] [review]
dont-wait-for-bg

Review of attachment 8365878 [details] [diff] [review]:
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Makes sense. r=me

Comment 4

[Terrence Cole [:terrence]]

Comment on attachment 8365879 [details] [diff] [review]
dont-recompact

Review of attachment 8365879 [details] [diff] [review]:
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Great! I'd been holding off on doing this because I couldn't think of a clean way to signal usage -- using the size is a nice solution. r=me

Comment 5

[Jon Coppeard (:jonco)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/3fd32a07dcca
https://hg.mozilla.org/integration/mozilla-inbound/rev/34ac931fc286

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/3fd32a07dcca
https://hg.mozilla.org/mozilla-central/rev/34ac931fc286