[aarch64-port-dev ] Request for review JDK-8140588 - Internal Error: gc/g1/ptrQueue.hpp:126 assert(_index == _sz) failed: invariant: queues are empty when activated

[Alexander Harlap]

Please review change forJDK-8140588 
<https://bugs.openjdk.java.net/browse/JDK-8140588> - Internal Error: 
gc/g1/ptrQueue.hpp:126 assert(_index == _sz) failed: invariant: queues 
are empty when activated

Change is located at http://cr.openjdk.java.net/~aharlap/8140588/webrev.00/

It implements Per Liden fix for rechecking value of marking in progress 
value inside C1 g1_pre_barrier code.

Also here is optimization described by Thomas Schatzl - do recheck only 
if patching involved.


Alex