[EXTERNAL] Re: Moving Forward with AHS for G1

[Monica Beckwith]

Hi Man,

Thanks for the update — great to see your patch moving forward.

Your changes look well-aligned with the direction Thomas outlined and what I summarized earlier: SoftMaxHeapSize guiding committed memory, integrated into resizing and IHOP logic, without overriding other tunables or introducing hard caps.

I’ve updated JDK-8236073 to reflect both your and Thomas’s contributions and reassigned it to you. This change forms a solid foundation as we move toward a more responsive, multi-signal controller (AHS) for G1.

Appreciate you picking this up and looking forward to seeing the PR evolve.

Best,
Monica



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________________________________
From: Man Cao <manc at google.com>
Sent: Friday, March 21, 2025 5:54 PM
To: Monica Beckwith <Monica.Beckwith at microsoft.com>
Cc: Thomas Schatzl <thomas.schatzl at oracle.com>; hotspot-gc-dev at openjdk.org <hotspot-gc-dev at openjdk.org>
Subject: [EXTERNAL] Re: Moving Forward with AHS for G1

Thank you for the summary and volunteering on this work! Apology for the lack of response from our side, due to other tasks and priorities.
I have been experimenting with implementing SoftMaxHeapSize for G1 (JDK-8236073), and using this knob instead of ProposedHeapSize for Google's AHS project. I could probably send out a Github PR next week.
>From our side, we would really like to make sure the implementation for SoftMaxHeapSize (JDK-8236073) and CurrentMaxHeapSize (JDK-8204088) work with Google's AHS project. It would be more effective if we could test with our internal workload and benchmarks during development.
Is it OK if I pick up the work for SoftMaxHeapSize (JDK-8236073) and CurrentMaxHeapSize (JDK-8204088)?

-Man
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