Allocate G1ParScanThreadState at the start of GC and only deallocate at the end of GC. This automatically keeps the current PLAB intact without flushing it (and loosing lots of memory) for every reallocation.
Reviewed-by: david, mgerdin
Remember for every generation whether the memory for that generation has already been exhausted. If so, do not try to get a new region for these generations. Further, if the last generation is full, early exit from copy_to_survivor_space.
Reviewed-by: jmasa, brutisso
Use the regular task queue during evacuation failure and allow per-thread preserved header queues to remove the global lock during evacuation failure.
Reviewed-by: mgerdin, jmasa
