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

src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp line 44:

> 42: #include "signals_posix.hpp"
> 43: 
> 44: const int64_t AUTOADAPT_INTERVAL_MS = 100;

static

src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp line 738:

> 736: }
> 737: 
> 738: const int SIG = SIGPROF;

static

src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp line 809:

> 807: 
> 808: 
> 809: int64_t compute_sampling_period(double rate) {

static

src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp line 854:

> 852: static bool _showed_warning = false;
> 853: 
> 854: void warn() {

static

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PR Review Comment: https://git.openjdk.org/jdk/pull/20752#discussion_r1825811189
PR Review Comment: https://git.openjdk.org/jdk/pull/20752#discussion_r1825812025
PR Review Comment: https://git.openjdk.org/jdk/pull/20752#discussion_r1825812255
PR Review Comment: https://git.openjdk.org/jdk/pull/20752#discussion_r1825812447