RFR: 8342818: Implement JEP 509: JFR CPU-Time Profiling [v35]

[Markus Grönlund]

On Tue, 3 Jun 2025 12:29:39 GMT, Markus Grönlund <mgronlun at openjdk.org> wrote:

>> Johannes Bechberger has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - Fix include order
>>  - Tiny refactoring
>
> src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp line 235:
> 
>> 233: 
>> 234: void JfrCPUTimeThreadSampler::on_javathread_create(JavaThread* thread) {
>> 235:   if (thread->is_Compiler_thread()) {
> 
> is_hidden_from_external_view() + is_JfrRecorderThread() instead?

tl->is_excluded() is volatile and can change during runtime, so it's better to add a timer unconditionally there.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25302#discussion_r2123669984