RFR: 8350314: Shenandoah: Capture thread state sync times in GC timings [v2]

[William Kemper]

On Tue, 25 Feb 2025 23:45:21 GMT, William Kemper <wkemper at openjdk.org> wrote:

>> Xiaolong Peng has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Address review comments
>
> src/hotspot/share/gc/shenandoah/shenandoahConcurrentGC.cpp line 1081:
> 
>> 1079:     heap->pacer()->setup_for_update_refs();
>> 1080:   }
>> 1081:   {
> 
> This one isn't necessary. This safepoint only happens when the pacer or the verifier is enabled. We moved init update ref gc state propagation into a handshake (see `ShenandoahHeap::concurrent_prepare_for_update_refs`). Sorry, I should have caught this in my first review.

I'm also currently working on removing the `final_roots` safepoint and fixing up the phase timings for the newish concurrent init update refs phase.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/23759#discussion_r1970696214