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

Summary: Replaced MakeDeps and the includeDB files with more standardized solutions.
Reviewed-by: coleenp, kvn, kamg

Summary: When an entry is stolen, don't push it on the task queue but process it directly.
Reviewed-by: iveresov, ysr, jcoomes

Reviewed-by: iveresov, tonyp

6942771: SEGV in ParScanThreadState::take_from_overflow_stack
Reviewed-by: apetrusenko, ysr, pbk

Summary: Associate number of GC workers with the workgang as opposed to the task.
Reviewed-by: johnc, ysr

Summary: This change revamps the slow allocation path of G1. Improvements include the following: a) Allocations directly to old regions are now totally banned. G1 now only allows allocations out of young regions (with the only exception being humongous regions). b) The thread that allocates a new region (which is now guaranteed to be young) does not dirty all its cards. Each thread that successfully allocates out of a young region is now responsible for dirtying the cards that corresponding to the "block" that just got allocated. c) allocate_new_tlab() and mem_allocate() are now implemented differently and TLAB allocations are only done by allocate_new_tlab(). d) If a thread schedules an evacuation pause in order to satisfy an allocation request, it will perform the allocation at the end of the safepoint so that the thread that initiated the GC also gets "first pick" of any space made available by the GC. e) If a thread is unable to allocate a humongous object it will schedule an evacuation pause in case it reclaims enough regions so that the humongous allocation can be satisfied aftewards. f) The G1 policy is more careful to set the young list target length to be the survivor number +1. g) Lots of code tidy up, removal, refactoring to make future changes easier.
Reviewed-by: johnc, ysr

Summary: as the title says, sometimes we are allocating humongous objects in young regions and we shouldn't.
Reviewed-by: ysr, johnc

Reviewed-by: tonyp, ysr

Summary: The per-worker _new_refs array is used to hold references that point into the collection set. It is populated during RSet updating and subsequently processed. In the event of an evacuation failure it processed again to recreate the RSets of regions in the collection set. Remove the per-worker _new_refs array by processing the references directly. Use a DirtyCardQueue to hold the cards containing the references so that the RSets of regions in the collection set can be recreated when handling an evacuation failure.
Reviewed-by: iveresov, jmasa, tonyp

Summary: G1 was not handling explicit GCs correctly in many ways. It does now. See the CR for the list of improvements contained in this changeset.
Reviewed-by: iveresov, ysr, johnc

Summary: Change all the Sun copyrights to Oracle copyright
Reviewed-by: ohair

Summary: Small improvements to G1's PrintGCDetails output. It also includes minor formatting details.
Reviewed-by: ysr, johnc

6871109: G1: remove the concept of the scan only prefix
Summary: Removed scan only regions and associated code. The young portion of the collection set is now constructed incrementally - when a young region is retired as the current allocation region it is added to the collection set.
Reviewed-by: apetrusenko, iveresov, tonyp

Summary: Replaces the G1-specific parameter with the existing ones that are used by the other GCs (YoungPLABSize and OldPLABSize)
Reviewed-by: tonyp, johnc

Summary: A TLAB became large enough to be considered a humongous object allowing multiple objects to be allocated in a humongous region, which violates a basic assumption about humongous regions. The changes ensure that TLABs cannot be regarded as humongous.
Reviewed-by: iveresov, tonyp

Summary: Use an explicit stack for object arrays and process them in chunks.
Reviewed-by: iveresov, apetrusenko

Summary: Implemented block-based work stealing. Moved copying during the rset scanning phase to the main copying phase. Made the size of rset table depend on the region size.
Reviewed-by: apetrusenko, tonyp

Summary: G1 now answers "no" to the query can_elide_initializing_store_barrier() in the product build. A debug flag allows alternate behaviour in debug builds.
Reviewed-by: iveresov, tonyp

Summary: Deferred card marks are now flushed during the gc prologue. Parallel[Scavege,OldGC] and SerialGC no longer defer card marks generated by COMPILER2 as a result of ReduceInitialCardMarks. For these cases, introduced a diagnostic option to defer the card marks, only for the purposes of testing and diagnostics. CMS and G1 continue to defer card marks. Potential performance concern related to single-threaded flushing of deferred card marks in the gc prologue will be addressed in the future.
Reviewed-by: never, johnc

Summary: G1 reports committed memory instead of reserved memory from the Runtime.maxMemory() method
Reviewed-by: ysr, jmasa

6889757: G1: enable card mark elision for initializing writes from compiled code (ReduceInitialCardMarks)
Summary: Defer the (compiler-elided) card-mark upon a slow-path allocation until after the store  and before the next subsequent safepoint; G1 now answers yes to can_elide_tlab_write_barriers().
Reviewed-by: jcoomes, kvn, never

Summary: Instead of the region size being hard-coded, allow the user to set it.
Reviewed-by: jmasa, johnc, apetrusenko

Summary: Treat ProfileData in MDO's as a source of weak, not strong, roots. Fixes the bug for stop-world collection -- the case of concurrent collection will be fixed separately.
Reviewed-by: jcoomes, jmasa, kvn, never

Summary: The used() method assumes that the heap lock is held when it is called. However, when used() is called from print_on(), this is not the case.
Reviewed-by: ysr, jmasa

Summary: Modifications to G1 so as to allow the use of compressed oops.
Reviewed-by: apetrusenko, coleenp, jmasa, kvn, never, phh, tonyp

Summary: Changing the behavior of -XX:+PrintHeapAtGC for G1 from printing lengthy, per-region information to instead printing a concise summary.
Reviewed-by: ysr, apetrusenko, jcoomes

Summary: extend G1 marking verification to use either the "prev" or "next" marking information, as appropriate.
Reviewed-by: johnc, ysr

Summary: For heaps larger than 32Gb, the number of heap regions overflows the data type used to hold the region index in the SparsePRT structure. Changed the region indexes, card indexes, and RSet hash table buckets to ints and added some size overflow guarantees.
Reviewed-by: ysr, tonyp

Reviewed-by: iveresov, tonyp

Summary: Make object_iterate() traverse the perm gen
Reviewed-by: apetrusenko, tonyp

Reviewed-by: iveresov, tonyp

6728271: G1: Cleanup G1CollectedHeap::get_gc_alloc_regions()
Summary: It allows the last half-full region to be allocated to during a GC to be reused during the next GC.
Reviewed-by: apetrusenko, jcoomes

Summary: Update copyright for files that have been modified in 2009, up to 03/09
Reviewed-by: katleman, tbell, ohair

6720334: G1: don't update RSets of collection set regions during an evacuation pause
Summary: Introduced a deferred update mechanism for delaying the rset updates during the collection pause
Reviewed-by: apetrusenko, tonyp

6797754: G1: combined bugfix
Summary: Implemented a policy to control G1 survivor space parameters.
Reviewed-by: tonyp, iveresov

Summary: A bunch of performance optimizations to decrease GC pause times in G1.
Reviewed-by: apetrusenko, jmasa, iveresov

Summary: Added safe_object_iterate() for use by JMapPerm.
Reviewed-by: tonyp