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/jdk/jfr/event/profiling/TestCPUTimeSampleThrottling.java line 65:

> 63:     private static void testThrottleSettingsPeriod() throws Exception {
> 64:         float rate = countEvents(1000, "1ms").rate();
> 65:         Asserts.assertTrue(rate > 950 && rate < 1050, "Expected around 1000 events per second, got " + rate);

Fails on linux-aarch64-debug builds:

----------System.out:(0/0)----------
----------System.err:(14/1061)----------
java.lang.RuntimeException: Expected around 1000 events per second, got 245.15503: expected true, was false
	at jdk.test.lib.Asserts.fail(Asserts.java:691)
	at jdk.test.lib.Asserts.assertTrue(Asserts.java:543)
	at jdk.jfr.event.profiling.TestCPUTimeEventThrottling.testThrottleSettingsPeriod(TestCPUTimeEventThrottling.java:65)
	at jdk.jfr.event.profiling.TestCPUTimeEventThrottling.main(TestCPUTimeEventThrottling.java:49)
	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)

JavaTest Message: Test threw exception: java.lang.RuntimeException: Expected around 1000 events per second, got 245.15503: expected true, was false
JavaTest Message: shutting down test

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

PR Review Comment: https://git.openjdk.org/jdk/pull/20752#discussion_r1824374656