On Tue, 3 Jun 2025 12:39:47 GMT, Johannes Bechberger <jbechber...@openjdk.org> wrote:
>> This is the code for the [JEP 509: CPU Time based profiling for >> JFR](https://openjdk.org/jeps/509). >> >> Currently tested using [this test >> suite](https://github.com/parttimenerd/basic-profiler-tests). This runs >> profiles the [Renaissance](https://renaissance.dev/) benchmark with >> - ... different heap sizes >> - ... different GCs >> - ... different samplers (the standard JFR and the new CPU Time Sampler and >> both) >> - ... different JFR recording durations >> - ... different chunk-sizes > > Johannes Bechberger has updated the pull request incrementally with one > additional commit since the last revision: > > Restrict threads for which timers are created src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp line 327: > 325: JfrThreadLocal* tl = jt->jfr_thread_local(); > 326: if (tl->wants_async_processing_of_cpu_time_jfr_requests()) { > 327: if (!jt->has_last_Java_frame() || jt->thread_state() != > _thread_in_native || !tl->try_acquire_cpu_time_jfr_dequeue_lock()) { I recommend this order for higher probability: 1. jt->thread_state() != _thread_in_native 2. !tl->try_acquire_cpu_time_jfr_dequeue_lock() 3. !jt->has_last_Java_frame() You need to restructure of course, to get the unlocking correct. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/25302#discussion_r2123711980
