On Tue, 3 Jun 2025 14:09:29 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: > > Rename autoadapt src/hotspot/share/jfr/periodic/sampling/jfrThreadSampling.cpp line 360: > 358: tl->set_do_async_processing_of_cpu_time_jfr_requests(false); > 359: if (lock) { > 360: tl->acquire_cpu_time_jfr_dequeue_lock(); This is your synchronization point on return from native code, which is effectively a spinlock. This can cause problems when a large number of threads are being processed by the "do_async_processing" request call. We should fix this as a bug after integration (use a proper Monitor as a synchronization point). ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/25302#discussion_r2124997140
