1487273 - Consider to add a limit how often forget skippable only cycles run

Status: RESOLVED FIXED

(Core :: XPCOM, enhancement, P3)

Description

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

nsJSContext::MaybePokeCC() uses NS_CC_SKIPPABLE_DELAY for IdleTaskRunner's timeout. I think we could increase that if sCleanupsSinceLastGC > NS_MAJOR_FORGET_SKIPPABLE_CALLS, since that means we've stopped the forget skippable run already at least once, and because GC hasn't run, we don't do new major runs, so forgetskippable is less important.

Comment 1

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

This might not help too much. We need a separate limit for forget skippable only cycles.
Re-purposing a bit.

Comment 2

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

Attachment: forget_skippable_limit.diff

Something like this.
I wouldn't want to land this, or any changes to forget skippable scheduling to FF63, so whatever is done in this bug should land after 2018-09-04.
Given the telemetry I added, this could show frequency to drop.

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Comment 3

[Andrew McCreight [:mccr8]]

Comment on attachment 9005738 [details] [diff] [review]
forget_skippable_limit.diff

Review of attachment 9005738 [details] [diff] [review]:
-----------------------------------------------------------------

::: dom/base/nsJSEnvironment.cpp
@@ +119,5 @@
>  #define NS_CC_DELAY                 6000 // ms
>  
>  #define NS_CC_SKIPPABLE_DELAY       250 // ms
>  
> +// In case cycle collector isn't run at all, we don't want

nit: I think you should add "the" between "case" and "cycle".

Comment 4

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

Attachment: forget_skippable_limit.diff

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/634170c72bf7
add a limit how often forget skippable only cycles run, r=mccr8

Comment 6

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/634170c72bf7