RFR: 8315149: Add hsperf counters for CPU time of internal GC threads [v32]

[Man Cao]

On Wed, 25 Oct 2023 20:37:46 GMT, Jonathan Joo <jjoo at openjdk.org> wrote:

>> 8315149: Add hsperf counters for CPU time of internal GC threads
>
> Jonathan Joo has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Use 64-bit atomic add for incrementing counters

The change LGTM except a small suggestion.
Could some one from hotspot-gc-dev also take a look as @albertnetymk added the tag?

src/hotspot/share/gc/shared/stringdedup/stringDedupProcessor.cpp line 200:

> 198:     log_statistics();
> 199:     if (UsePerfData && os::is_thread_cpu_time_supported()) {
> 200:       ThreadTotalCPUTimeClosure tttc(_concurrent_dedup_thread_cpu_time, true);

I think it is better to not classify StringDedup thread as a GC thread, so remove the "true" parameter.
Although StringDedup requests are initiated during GC (search `_string_dedup_requests.add`), they are not part of the GC.

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

Marked as reviewed by manc (Committer).

PR Review: https://git.openjdk.org/jdk/pull/15082#pullrequestreview-1698265647
PR Review Comment: https://git.openjdk.org/jdk/pull/15082#discussion_r1372333757