RFR: 8365922: Parallel: Group uses of GCTimeRatio to a single location

[Albert Mingkun Yang]

On Tue, 26 Aug 2025 08:16:25 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

>> Unify all accesses of `GCTimeRatio` to a single place so that Parallel gets a coherence view of its value within the pause, if the global variable's value is ever changed.
>> 
>> Test: tier1-3
>
> src/hotspot/share/gc/parallel/psAdaptiveSizePolicy.cpp line 90:
> 
>> 88: 
>> 89:   // Get a local copy and use it inside gc-pause in case the global var gets updated externally.
>> 90:   const uint local_GCTimeRatio = GCTimeRatio;
> 
> needs an `Atomic::load()` as the compiler is free to re-read the global later at any use of the local.

I was thinking to add that when this flag actually becomes manageable. I don't feel too strongly about it. Do you prefer using atomic already now?

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

PR Review Comment: https://git.openjdk.org/jdk/pull/26881#discussion_r2300206747