RFR (L) 8186777: Make Klass::_java_mirror an OopHandle

[coleen.phillimore at oracle.com]

On 9/6/17 12:04 PM, coleen.phillimore at oracle.com wrote:
> Summary: Add indirection for fetching mirror so that GC doesn't have 
> to follow CLD::_klasses
>
> Thank you to Tom Rodriguez for Graal changes and Rickard for the C2 
> changes.
>
> Ran nightly tests through Mach5 and RBT.   Early performance testing 
> showed good performance improvment in GC class loader data processing 
> time, but nmethod processing time continues to dominate. Also 
> performace testing showed no throughput regression.   I'm rerunning 
> both of these performance testing and will post the numbers.
>
> bug link https://bugs.openjdk.java.net/browse/JDK-8186777
> local webrev at 
> http://oklahoma.us.oracle.com/~cphillim/webrev/8186777.01/webrev
Sorry, the open webrev at 
http://cr.openjdk.java.net/~coleenp/8186777.01/webrev

Coleen
>
> Thanks,
> Coleen