JDK 9 RFR of JDK-8081734 : ConcurrentHashMap/ConcurrentAssociateTest.java, times out 90% of time on sparc with 256 cpu.

[Chris Hegarty]

This seems reasonable to me Joe.

-Chris.

> On 20 Jul 2015, at 22:15, joe darcy <joe.darcy at oracle.com> wrote:
> 
> Hello,
> 
> Please review a small change to adders
> 
>    JDK-8081734 : ConcurrentHashMap/ConcurrentAssociateTest.java, times out 90% of time on sparc with 256 cpu.
>    http://cr.openjdk.java.net/~darcy/8081734.0/
> 
> Patch below.
> 
> Some background, when run on large machines, 256 processors/threads, this test takes many minutes to run due to hitting some degenerate conditions. Bounding the concurrency to 32 serves the purposes of checking for the conditions the test was written for while also allowing a reasonable execution time for a single test.
> 
> Thanks,
> 
> -Joe
> 
> --- old/test/java/util/concurrent/ConcurrentHashMap/ConcurrentAssociateTest.java 2015-07-20 14:08:23.839018642 -0700
> +++ new/test/java/util/concurrent/ConcurrentHashMap/ConcurrentAssociateTest.java 2015-07-20 14:08:23.679018638 -0700
> @@ -120,7 +120,8 @@
>             }
>         };
> 
> -        int ps = Runtime.getRuntime().availableProcessors();
> +        // Bound concurrency to avoid degenerate performance
> +        int ps = Math.min(Runtime.getRuntime().availableProcessors(), 32);
>         Stream<CompletableFuture> runners = IntStream.range(0, ps)
>                 .mapToObj(i -> sr.get())
>                 .map(CompletableFuture::runAsync);
>