RFR(S): 8166738 - Enable concurrency in Hotspot jtreg testing

[Erik Joelsson]

Looks good to me.

/Erik

On 2016-09-26 23:07, Christian Tornqvist wrote:
>
> Hi everyone,
>
> Please review this small change that enables concurrency for the 
> Hotspot jtreg tests when running them through the make system. Testing 
> done so far shows very promising speed ups, both when running locally 
> and in JPRT.
>
> It’ll automatically calculate a sane concurrency number based on the 
> number of cores / 2 (with a maximum of 12) and then sets 
> MaxRAMFraction=concurrency*4 to make sure we don’t run out of memory. 
> The concurrency value can be overridden by setting TEST_JOBS to the 
> desired concurrency value.
>
> On Windows, this change is temporarily commented out since we run into 
> the intermittent issue described in JDK-8159799.
>
> Webrev:
>
> http://cr.openjdk.java.net/~ctornqvi/webrev/8166738/webrev.00/ 
> <http://cr.openjdk.java.net/%7Ectornqvi/webrev/8166738/webrev.00/>
>
> Bug:
>
> https://bugs.openjdk.java.net/browse/JDK-8166738
>
> Thanks,
>
> Christian
>