RFR: 8369609: Continuations preempt_epilog is missing a call to invalidate_jvmti_stack [v2]

[Serguei Spitsyn]

On Mon, 20 Oct 2025 21:59:40 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> Serguei Spitsyn has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   review: remove now unneeded call to invalidate_jvmti_stack
>
> src/hotspot/share/runtime/continuationFreezeThaw.cpp line 1689:
> 
>> 1687:   log_develop_debug(continuations)("=== End of freeze cont ### #" INTPTR_FORMAT, cont.hash());
>> 1688: 
>> 1689:   JVMTI_ONLY(invalidate_jvmti_stack(JavaThread::current()));
> 
> Why not directly in `preempt_epilog`? Is it to cover the freeze fast case too? If that’s the case we should remove the call to `invalidate_jvmti_stack` from `jvmti_yield_cleanup` to avoid calling it twice for the freeze slow case. Also I wonder if this call to `invalidate_jvmti_stack` should just be moved to `JvmtiVTMSTransitionDisabler::VTMS_unmount_end` instead.

Yes, I had in mind but forgot to remove the call to `invalidate_jvmti_stack()` from `jvmti_yield_cleanup()`. I've pushed the update now.

> Also I wonder if this call to invalidate_jvmti_stack should just be moved to JvmtiVTMSTransitionDisabler::VTMS_unmount_end instead.

Unfortunately, this is not going to work for plain/pure continuations as `mount/unmount` code path does not work for them.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27878#discussion_r2450180606