Open Bug 1634469 Opened 5 years ago Updated 25 days ago

Disable JITs for chrome JS in unimportant iframe content processes

Categories

(Core :: DOM: Content Processes, task, P3)

task

Tracking

()

Tracking Status
firefox-esr68 --- wontfix
firefox75 --- wontfix
firefox76 --- wontfix
firefox77 --- fix-optional

People

(Reporter: mccr8, Unassigned)

References

(Blocks 1 open bug)

Details

This is just a wild idea I had, but I wonder how much memory we could save by disabling JITs for ad iframes, given that we'll probably not be able to disable it entirely.

Maybe the JITs are adaptive enough that they'll drop whatever extra memory they use in a cold process.

Do you think this would save much memory?

Flags: needinfo?(jdemooij)
Severity: -- → normal
Priority: -- → P3

(In reply to Andrew McCreight [:mccr8] from comment #2)

Do you think this would save much memory?

As far as I know we're pretty good at discarding JIT code periodically. Releasing the JitScript will discard all JIT code + IC data + StackTypeSets for the script.

What does take up quite a lot of space is TI data for property types. As part of WarpBuilder work it's now possible (and necessary) to turn off a lot of TI, but it's mostly an untested configuration and it doesn't give you all the memory wins yet so I'm hesitant about using that.

WarpBuilder is progressing well so unless this is critical I'd suggest waiting for that to mature. Maybe we could enable WarpBuilder first in the parent process + these iframe processes to save memory. Once WarpBuilder is the default everywhere, we can remove ObjectGroups entirely, and that will save even more memory.

Flags: needinfo?(jdemooij)

The severity field is not set for this bug.
:neha, could you have a look please?

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Flags: needinfo?(nkochar)
Severity: normal → N/A
Type: defect → task
Flags: needinfo?(nkochar)
See Also: → 1562636
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