RFR: 8360046: Scalability issue when submitting virtual threads with almost empty tasks [v10]

Viktor Klang vklang at openjdk.org
Mon Sep 22 11:04:58 UTC 2025


On Sat, 20 Sep 2025 17:32:31 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:
> 
>   Add @Contended WorkQueue region. Adapt accordingly.

src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java line 2118:

> 2116:     private int tryTrim(WorkQueue w, int activePhase, long deadline) {
> 2117:         long c, nc; int stat, vp, i; WorkQueue[] vs; WorkQueue v;
> 2118:         long waitTime = deadline - System.currentTimeMillis();

Why hoist this line from the branch? 🤔

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

PR Review Comment: https://git.openjdk.org/jdk/pull/26479#discussion_r2367691693


More information about the core-libs-dev mailing list