RFR: Ensure tasks use correct number of workers

[Zhengyu Gu]

On 09/18/2017 09:10 AM, Aleksey Shipilev wrote:
> On 09/18/2017 02:42 PM, Zhengyu Gu wrote:
>> Ensure that GC tasks follow parallel/concurrent worker protocol, use correct number of worker threads.
>>
>> Webrev: http://cr.openjdk.java.net/~zgu/shenandoah/assert_workers/webrev.00/
> 
> *) I see that ShenandoahCollectorPolicy computes the number of workers for different phases. Do we
> want at least do the call to to policy, instead of using ParallelGCThreads/ConcGCThreads directly?
> This will capture all worker count decisions, however static, in one place.

Let's do it separately. It does not cover all scenarios, I think.

> 
> *) How long is TestGCThreadGroups? It seems to be derived from LotsOfCycles test, but we can really
> do much smaller allocation target, e.g. 10x lower?

It did not timeout. Okay to lower target to 1/10 - Done.

> 
> *) Typo "SWT":
> 
>   257 void ShenandoahPartialGC::do_partial_collection() {
>   258   assert(SafepointSynchronize::is_at_safepoint(), "SWT partial GC");
> 
> *) Type "none-regular":
> 
>    44   // bypass concurrent/parallel protocol check for none-regular paths, e.g. verifier, etc.
> 

Fixed.

Updated: 
http://cr.openjdk.java.net/~zgu/shenandoah/assert_workers/webrev.01/


Thanks,

-Zhengyu

> Thanks,
> -Aleksey
>