It turns out that there is no need to explicitly stop CMS since the JVM is taken down at a terminal safepoint during which CMS threads are (terminally) inactive. This will need to be revised if and when we evolve in the future to a point where we allow JVM reincarnation in the same process, but those changes will be much more sweeping than just terminating CMS threads. The unused ::stop() methods will be removed in a separate CR. Also include in this CR is the fix for a small typo in the spelling of UseGCLogFileRotation in a message in arguments.cpp, brought to our attention by Rainer Jung and reviewed by minqi.
Reviewed-by: johnc, jwilhelm
7042285: G1: native memory leak during humongous object allocation
6804436: G1: heap region indices should be size_t
A series of fixes and improvements to the HeapRegionSeq class: a) replace the _regions growable array with a standard C array, b) avoid de-allocating / re-allocating HeapRegion instances when the heap shrinks / grows (fix for 7042285), c) introduce fast method to map address to HeapRegion via a "biased" array pointer, d) embed the _hrs object in G1CollectedHeap, instead of pointing to it via an indirection, e) assume that all the regions added to the HeapRegionSeq instance are contiguous, f) replace int's with size_t's for indexes (and expand that to HeapRegion as part of 6804436), g) remove unnecessary / unused methods, h) rename a couple of fields (_alloc_search_start and _seq_bottom), i) fix iterate_from() not to always start from index 0 irrespective of the region passed to it, j) add a verification method to check the HeapRegionSeq assumptions, k) always call the wrappers for _hrs.iterate(), _hrs_length(), and _hrs.at() from G1CollectedHeap, not those methods directly, and l) unify the code that expands the sequence (by either re-using or creating a new HeapRegion) and make it robust wrt to a HeapRegion allocation failing.
Reviewed-by: stefank, johnc, brutisso
This changeset extends the logging information generated by +PrintGCDetails to also print out separate size transitions for the eden, survivors, and old regions.
Reviewed-by: ysr, brutisso
The LNC array is sized before the start of a scavenge, while the heap may expand during a scavenge. With CMS, the last block of an arbitrary suffice of the LNC array may expand due to coalition with the expansion delta. We now take care not to attempt access past the end of the LNC array. LNC array code will be cleaned up and suitably encapsulated as part of the forthcoming performance RFE 7043675.
Reviewed-by: brutisso
The freeness bit was being cleared in debug code when it shouldn't have been. Also removed unused FreeChunk methods linkAfterNonNull and clearPrev.
Reviewed-by: brutisso
Do a one-step look-ahead, when sweeping free or garbage blocks, to avoid overstepping sweep limit, which may become a non-block-boundary because of a heap expansion delta coalescing with a previously co-terminal free block.
Reviewed-by: brutisso, tonyp
