RFR: 8342818: Implement CPU Time Profiling for JFR [v4]

[Markus Grönlund]

On Wed, 30 Oct 2024 19:34:23 GMT, Johannes Bechberger <jbechberger at openjdk.org> wrote:

>> This is the code for the [JEP draft: CPU Time based profiling for JFR].
>
> Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove min_valid_free_size_bytes

Test: jdk/jfr/jcmd/TestJcmdStartWithOptions.java seems to be timing out when the CPU Time Profiler is turned on.

Test: TestActiveSettingEvent also have problems on Linux, not only on non-Linux platforms.

Testing configuration default
----------System.err:(15/1230)----------
java.lang.RuntimeException: Incorrect settings value for jdk.CPUTimeSample#throttle was 0/s, expected 500/s expected: 500/s but was: 0/s
	at jdk.test.lib.Asserts.fail(Asserts.java:691)
	at jdk.test.lib.Asserts.assertEquals(Asserts.java:204)
	at jdk.jfr.event.runtime.TestActiveSettingEvent.testSettingConfiguration(TestActiveSettingEvent.java:308)
	at jdk.jfr.event.runtime.TestActiveSettingEvent.testDefaultSettings(TestActiveSettingEvent.java:79)
	at jdk.jfr.event.runtime.TestActiveSettingEvent.main(TestActiveSettingEvent.java:65)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
	at java.base/java.lang.reflect.Method.invoke(Method.java:573)
	at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
	at java.base/java.lang.Thread.run(Thread.java:1576)

-------------

PR Comment: https://git.openjdk.org/jdk/pull/20752#issuecomment-2449751577
PR Comment: https://git.openjdk.org/jdk/pull/20752#issuecomment-2449756140