Age bits need not enter the mark-word preservation calculus; also affected, in addition to CMS, per CR synopsis above, were ParNew (but not DefNew), ParallelScavenge and G1, albeit to a lesser degree than CMS.
Reviewed-by: tonyp, johnc
7002546: regression on SpecJbb2005 on 7b118 comparing to 7b117 on small heaps
Relaxed assertion checking related to incremental_collection_failed flag to allow for ExplicitGCInvokesConcurrent behaviour where we do not want a failing scavenge to bail to a stop-world collection. Parameterized incremental_collection_will_fail() so we can selectively use, or not use, as appropriate, the statistical prediction at specific use sites. This essentially reverts the scavenge bail-out logic to what it was prior to some recent changes that had inadvertently started using the statistical prediction which can be noisy in the presence of bursty loads. Added some associated verbose non-product debugging messages.
Reviewed-by: johnc, tonyp
Sharpened an assert, introduced in 6896603, that intended to check that the incremental_collection_failed() predicate on the heap was being reset "soon enough".
Reviewed-by: jmasa
Deprecated HandlePromotionFailure, removing the ability to turn off that feature, did away with one epoch look-ahead when deciding if a scavenge is likely to fail, relying on current data.
Reviewed-by: jmasa, johnc, poonam
Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking.
Reviewed-by: jmasa
For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa
