7016998: gcutil class LinearLeastSquareFit doesn't initialize some of its fields Summary: Initialize _sum_x_squared, _intercept and _slope in constructor. Reviewed-by: bobv, coleenp

6923430: G1: assert(res != 0,"This should have worked.") 7007446: G1: expand the heap with a single step, not one region at a time Summary: Changed G1CollectedHeap::expand() to expand the committed space by calling VirtualSpace::expand_by() once rather than for every region in the expansion amount. This allows the success or failure of the expansion to be determined before creating any heap regions. Introduced a develop flag G1ExitOnExpansionFailure (false by default) that, when true, will exit the VM if the expansion of the committed space fails. Finally G1CollectedHeap::expand() returns a status back to it's caller so that the caller knows whether to attempt the allocation. Reviewed-by: brutisso, tonyp

6789220: CMS: intermittent timeout running nsk/regression/b4796926 Summary: The reference handler java thread and the GC could dead lock Reviewed-by: never, johnc, jcoomes

6999988: CMS: Increased fragmentation leading to promotion failure after CR#6631166 got implemented Summary: Fix calculation of _desired, in free list statistics, which was missing an intended set of parentheses. Reviewed-by: poonam, jmasa

7014679: G1: deadlock during concurrent cleanup Summary: There's a potential deadlock between the concurrent cleanup thread and the GC workers that are trying to allocate and waiting for more free regions to be made available. Reviewed-by: iveresov, jcoomes

Added tag hs21-b01 for changeset 251814950cb2