RFR: 8322732: ForkJoinPool may underutilize cores in async mode [v3]

[Doug Lea]

On Wed, 22 May 2024 15:51:05 GMT, Viktor Klang <vklang at openjdk.org> wrote:

>> Doug Lea has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 36 additional commits since the last revision:
>> 
>>  - Merge branch 'openjdk:master' into JDK-8322732
>>  - More performance tradoffs
>>  - Address review comments
>>  - Merge branch 'openjdk:master' into JDK-8322732
>>  - Repack some fields; adjust control flow
>>  - Merge branch 'openjdk:master' into JDK-8322732
>>  - Next version
>>  - Merge branch 'openjdk:master' into JDK-8322732
>>  - Reduce unneeded signals
>>  - Merge branch 'openjdk:master' into JDK-8322732
>>  - ... and 26 more: https://git.openjdk.org/jdk/compare/44041895...f1fc4f3e
>
> src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java line 1884:
> 
>> 1882:             else
>> 1883:                 nc = (v.stackPred & LMASK) | (c & TC_MASK);
>> 1884:             if (c == (c = compareAndExchangeCtl(c, nc | ac))) {
> 
> So the TTAS wasn't worth it on some architectures? 🤔

Right. so just added to code path

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PR Review Comment: https://git.openjdk.org/jdk/pull/19131#discussion_r1610783672