RFR: 8352251: Implement JEP 518: JFR Cooperative Sampling [v23]

[Patricio Chilano Mateo]

On Fri, 16 May 2025 22:12:08 GMT, Markus Grönlund <mgronlun at openjdk.org> wrote:

>> That is very good spotted indeed. There is a race here if the top frame is invalidated and we just go with the sender (it would describe the carrier frames for the vthread, something I had some problems with in the very beginning).
>> 
>> My neurons about Continuations and "rbp in continuations" are unfortunately way off in DRAM, on some remote  NUMA node to boot.
>> 
>> Can you help me think out how to handle the Continuation specific things in parsing here?
>
>> > Where do you suggest to place it best?
>> 
>> Should be in `FreezeBase::unwind_frames()`. That's where we change the anchor to the ContinuationEntry.
> 
> Fixed. Thanks.

> That is very good spotted indeed. There is a race here if the top frame is invalidated and we just go with the sender (it would describe the carrier frames for the vthread, something I had some problems with in the very beginning).
> 
> My neurons about Continuations and "rbp in continuations" are unfortunately way off in DRAM, on some remote NUMA node to boot.
> 
> Can you help me think out how to handle the Continuation specific things in parsing here?
>
Ok, no need to bring it to cache since this has been fixed (modulo the extra check discussed) with the new approach. : )

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PR Review Comment: https://git.openjdk.org/jdk/pull/24296#discussion_r2098390449