Reviewed-by: never, coleenp, ysr, jwilhelm

Summary: Use _max_num_q = max(discovery_degree, processing_degree), and let balance_queues() redistribute from discovery_degree to processing_degree of queues. This should also allow a more dynamic and flexible parallelism policy in the future.
Reviewed-by: jmasa, johnc

Summary: Count enable_icms() and disable_icms() events so as to prevent inteference between concurrent calls, which can cause the iCMS thread to be left stranded in icms_wait() with an unserviced request and no young allocations to unwedge it.
Reviewed-by: jcoomes, poonam

Summary: Check that -XX:ParGCArrayScanChunk has a value larger than zero.
Reviewed-by: johnc, jmasa, ysr

7023747: G1: too strict assert in RefineRecordRefsIntoCSCardTableEntryClosure::do_card_ptr in g1RemSet.cpp
Summary: Made sure that the assert looks at ParallelGCThreads.
Reviewed-by: stefank, tonyp, jwilhelm, johnc

Summary: Introduced buffered loggging to make sure that log lines are logged one line at a time
Reviewed-by: stefank, johnc, dsamersoff

Summary: Some G1 code cleanup.
Reviewed-by: johnc, jcoomes, jwilhelm

Summary: Bulk zeroing reduction didn't work with G1, because arraycopy would call pre-barriers on uninitialized oops. The solution is to have version of arraycopy stubs that don't have pre-barriers. Also refactored arraycopy stubs generation on SPARC to be more readable and reduced the number of stubs necessary in some cases.
Reviewed-by: jrose, kvn, never

Summary: Make the G1 specific version of is_in_closed_subset() available in all builds.
Reviewed-by: tonyp, jcoomes

Summary: Align old gen size down to keep specified heap size.
Reviewed-by: ysr

Summary: Removed.
Reviewed-by: jcoomes, brutisso

Summary: Fix block_size_if_printezis_bits() so it does not expect the bits, only uses them when available. Fix block_size_no_stall() so it does not stall when the bits are missing such cases, letting the caller deal with zero size returns. Constant pool cache oops do not need to be unparsable or conc_unsafe after their klass pointer is installed. Some cosmetic clean-ups and some assertion checking for conc-usafety which, in the presence of class file redefinition, has no a-priori time boundedness, so all GCs must be able to safely deal with putatively conc-unsafe objects in a stop-world pause.
Reviewed-by: jmasa, johnc

Summary: Sometimes the gc cause was not always set. This caused JStat to print the wrong information.
Reviewed-by: tonyp, ysr
Contributed-by: suenaga.yasumasa@oss.ntt.co.jp

Summary: Initialize _sum_x_squared, _intercept and _slope in constructor.
Reviewed-by: bobv, coleenp

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

Summary: Fix calculation of _desired, in free list statistics, which was missing an intended set of parentheses.
Reviewed-by: poonam, jmasa

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

Summary: move symbols from permgen into C heap and reference count them
Reviewed-by: never, acorn, jmasa, stefank

Summary: A race between the concurrent cleanup thread and the VM thread while it is processing the "expanded sparse table list" causes both threads to try to free the same sparse table entry and either causes one of the threads to fail or leaves the entry in an inconsistent state. The solution is purge all entries on the expanded list that correspond go regions that are being cleaned up.
Reviewed-by: brutisso, johnc

Summary: Implement support for ParallelRefProcEnabled in the reference processing that takes place at the end of G1 concurrent marking.
Reviewed-by: tonyp, ysr

Summary: Two small fixes to deal with a guarantee failure (the marking thread should join the SuspendibleThreadSet before calling a method that does pause prediction work so that said method is never called during a pause) and an assert failure (an assert is too strong).
Reviewed-by: iveresov, johnc

Summary: This changeset removes the zero-filling thread from G1 and collapses the two free region lists we had before (the "free" and "unclean" lists) into one. The new free list uses the new heap region sets / lists abstractions that we'll ultimately use it to keep track of all regions in the heap. A heap region set was also introduced for the humongous regions. Finally, this change increases the concurrency between the thread that completes freeing regions (after a cleanup pause) and the rest of the system (before we'd have to wait for said thread to complete before allocating a new region). The changest also includes a lot of refactoring and code simplification.
Reviewed-by: jcoomes, johnc

Summary: Rebuild breakpoint cache at gc_epilogue instead of during oops_do
Reviewed-by: dcubed, ysr, coleenp

Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads.
Reviewed-by: johnc, ysr

Summary: Revert a (relaxed version of the) bounds-check that was incorrectly removed in the fix for 7008136.
Reviewed-by: jmasa, johnc

Summary: Pass the value of UseLargePages instead of false as the "large" parameter when reserving the G1 heap.
Reviewed-by: tonyp, johnc, phh

Summary: First attempt to allocate out the current alloc region using a CAS instead of taking the Heap_lock (first level of G1's slow allocation path). Only if that fails and it's necessary to replace the current alloc region take the Heap_lock (that's the second level of G1's slow allocation path).
Reviewed-by: johnc, brutisso, ysr

Summary: During evacuation failure handling we refine the BOT to reflect the location of all the objects in the regions we scan. The changeset includes some minor cleanup: a) non-product print_on() method on the G1 BOT class, b) added more complete BOT verification during heap / region verification, c) slight modification to the BOT set up for humongous regions to be more consistent with the BOT set up during evac failure handling, and d) removed a couple of unused methods.
Reviewed-by: johnc, ysr

Summary: Make JvmtiGCMark safe to run non-safepoint and instrument CMS
Reviewed-by: ysr, dcubed

Summary: The recorded _sweep_limit may not necessarily remain a block boundary as the old generation expands during a concurrent cycle. Terminal actions inside the sweep closure need to be aware of this as they cross over the limit.
Reviewed-by: johnc, minqi

Summary: Fire the gc-begin and gc-end probes for G1.
Reviewed-by: kamg, ysr, jcoomes

Summary: 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

Summary: Initialize the _is_alive_non_header field of G1's reference processor with an instance of the G1CMIsAliveClosure. This will stop adding reference objects with live referents to the discovered reference lists unnecessarily.
Reviewed-by: tonyp, ysr, jwilhelm, brutisso

7000559: G1: assertion failure !outer || (full_collections_started == _full_collections_completed + 1)
Summary: The concurrent marking thread can complete its operation and increment the full GC counter during a Full GC. This causes the nesting of increments to the start and end of Full GCs that we are expecting to be wrong. the fix is for the marking thread to join the suspendible thread set before incrementing the counter so that it's blocked until the Full GC (or any other safepoint) is finished. The change also includes some minor code cleanup (I renamed a parameter).
Reviewed-by: brutisso, ysr

Summary: Relaxed the assert by allowing NULL referents when discovery may be concurrent.
Reviewed-by: johnc, jcoomes

7001033: assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed())
7002546: regression on SpecJbb2005 on 7b118 comparing to 7b117 on small heaps
Summary: 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

Summary: Allow the eden to the expanded up to a point when the GC locker is active.
Reviewed-by: jwilhelm, johnc, ysr, jcoomes

Summary: Wrong assumption about expecting the current alloc region expected to be NULL in expand_and_allocate().
Reviewed-by: brutisso, ysr

Summary: Enable reference discovery during concurrent marking by setting the reference processor field of the concurrent marking closure. Keep reference objects on the discovered reference lists alive during incremental evacuation pauses until they are processed at the end of concurrent marking.
Reviewed-by: ysr, tonyp

Summary: Added an ifndef DONT_USE_PRECOMPILED_HEADER to precompiled.hpp. Set up DONT_USE_PRECOMPILED_HEADER when compiling with Sun Studio or when the user specifies USE_PRECOMPILED_HEADER=0. Fixed broken include dependencies.
Reviewed-by: coleenp, kvn