RFR: 8360046: Scalability issue when submitting virtual threads with almost empty tasks [v5]

[Viktor Klang]

On Thu, 7 Aug 2025 14:03:40 GMT, Doug Lea <dl at openjdk.org> wrote:

>> This set of updates reduces contention-based performance loss under heavy over-subscription, while also improving perfomance more generally.
>
> Doug Lea has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Avoid underutilization on resize

src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java line 1290:

> 1288:                     if (room == 0) {                        // resize
> 1289:                         growArray(a, cap, s);
> 1290:                         a = null;

Suggestion:

                        a = null;  // Indicate resize to trigger signalling

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

PR Review Comment: https://git.openjdk.org/jdk/pull/26479#discussion_r2276372414