On Sat, 11 May 2024 23:39:04 GMT, Viktor Klang <vkl...@openjdk.org> wrote:
>> This set of changes address causes of poor utilization with small numbers of
>> cores due to overly aggressive contention avoidance. A number of further
>> adjustments were needed to still avoid most contention effects in
>> deployments with large numbers of cores
>
> src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java line 962:
>
>> 960: * minimum allowed timeout value.
>> 961: */
>> 962: static final long TIMEOUT_SLOP = 20L;
>
> Might be worth spelling out the temporal unit used here.
done.
> src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java line 1833:
>
>> 1831: if (phase != 0) { // else failed to start
>> 1832: replaceable = true;
>> 1833: if (w.top - w.base > 0) {
>
> @DougLea Is this check sufficiently cheaper than trying to poll blind?
Done.
> src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java line 1916:
>
>> 1914: */
>> 1915: private long releaseAll() {
>> 1916: long c = ctl;
>
> `ctl` is not re-read inside the endless loop, is there any risk for a stale
> `ctl` to make `releaseAll()` never terminate?
It is implicitly read via the compareAndExchangeCtl
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/19131#discussion_r1597633326
PR Review Comment: https://git.openjdk.org/jdk/pull/19131#discussion_r1597633209
PR Review Comment: https://git.openjdk.org/jdk/pull/19131#discussion_r1597633649
