On Tue, 8 Sep 2026 14:20:12 GMT, Per Minborg <[email protected]> wrote:
> This PR proposes to improve the performance of the newly integrated confined > arena cache. Confined arenas now remember the platform pool array and the > pool array index used for pool acquisition. Upon closing the arena, the pool > can be returned (in most cases) directly to the correct index in the confined > arena cache. > > If the opportunistic pool index is occupied, the logic falls back to the > regular path, which scans the array for an empty slot. > > The PR additionally proposes to add a test to make sure the unusual release > path works correctly. > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). Benchmark on an M4 Mac: Base: Benchmark (size) Mode Cnt Score Error Units AllocTest.OfVirtual.alloc_confined 5 avgt 30 3.261 ± 0.113 ns/op AllocTest.alloc_confined 5 avgt 30 1.072 ± 0.031 ns/op Patch: Benchmark (size) Mode Cnt Score Error Units AllocTest.OfVirtual.alloc_confined 5 avgt 30 3.106 ± 0.240 ns/op AllocTest.alloc_confined 5 avgt 30 0.817 ± 0.016 ns/op <-- about 24% improvement (on ns scale) ------------- PR Comment: https://git.openjdk.org/jdk/pull/32766#issuecomment-5586649832
