RFR: 8338383: Implement JEP 491: Synchronize Virtual Threads without Pinning

[David Holmes]

On Fri, 25 Oct 2024 13:11:18 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> src/hotspot/cpu/aarch64/interp_masm_aarch64.cpp line 1550:
>> 
>>> 1548: #endif /* ASSERT */
>>> 1549: 
>>> 1550:   push_cont_fastpath();
>> 
>> One of the callers of this gives a clue what it does.
>> 
>>   __ push_cont_fastpath(); // Set JavaThread::_cont_fastpath to the sp of the oldest interpreted frame we know about
>> 
>> Why do you do this here?  Oh please more comments...
>
> _cont_fastpath is what we check in freeze_internal to decide if we can take the fast path. Since we are calling from the interpreter we have to take the slow path. Added a comment.

It seems somewhat of an oxymoron that to force a slow path we push a fastpath. ???

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PR Review Comment: https://git.openjdk.org/jdk/pull/21565#discussion_r1818245043