Merge

6976350: G1: deal with fragmentation while copying objects during GC Summary: Create G1ParGCAllocBufferContainer to contain two buffers instead of previously using one buffer, in order to hold the first priority buffer longer. Thus, when some large objects hits the value of free space left in the first priority buffer it has an alternative to fit in the second priority buffer while the first priority buffer is given more chances to try allocating smaller objects. Overall, it will improve heap space efficiency. Reviewed-by: johnc, jmasa, brutisso Contributed-by: tamao <tao.mao@oracle.com>

8015244: G1: Verification after a full GC is incorrectly placed. Summary: In a full GC, move the verification after the GC to after RSet rebuilding. Verify RSet entries during a full GC under control of a flag. Reviewed-by: tschatzl, brutisso

8013895: G1: G1SummarizeRSetStats output on Linux needs improvemen Summary: Fixed the output of G1SummarizeRSetStats: too small datatype for the number of concurrently processed cards, added concurrent remembered set thread time retrieval for Linux and Windows (BSD uses os::elapsedTime() now), and other cleanup. The information presented during VM operation is now relative to the previous output, not always cumulative if G1SummarizeRSetStatsPeriod > 0. At VM exit, the code prints a cumulative summary. Reviewed-by: johnc, jwilhelm