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 26:

> 24: 
> 25: #include "precompiled.hpp"
> 26: #include "jfr/recorder/service/jfrOptionSet.hpp"

All includes except:

#include "precompiled.hpp"
#include "jfr/periodic/sampling/jfrCPUTimeThreadSampler.hpp"
#include "utilities/debug.hpp"

Can be moved below #if defined(Linux) (to reduce compilation time on non-Linux platforms)

src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp line 42:

> 40: 
> 41: #if defined(LINUX)
> 42: #include "signals_posix.hpp"

You will also need to include <sys/types.h> and change the type from OSThread::thread_id_t to pid_t, else you can get the following error:

"error: 'typedef pid_t OSThread::thread_id_t' is private within this context"

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

PR Review Comment: https://git.openjdk.org/jdk/pull/20752#discussion_r1823419528
PR Review Comment: https://git.openjdk.org/jdk/pull/20752#discussion_r1823424176