Summary: Ensure a full GC that clears SoftReferences before throwing an out-of-memory
Reviewed-by: ysr, jcoomes

Summary: Humongous regions may contain multiple objects as a result of being retained as to-space from a previous GC and then re-used as to-space after being tagged as humongous. These changes include a check that causes retained to-space regions that are now tagged as humongous to be disregarded and a new to-space region allocated.
Reviewed-by: tonyp, iveresov

Summary: Make sure that two marking cycles do not overlap, i.e., a new one can only start after the concurrent marking thread finishes all its work. In the fix I piggy-back a couple of minor extra fixes: some general code reformatting for consistency (only around the code I modified), the removal of a field (G1CollectorPolicy::_should_initiate_conc_mark) which doesn't seem to be used at all (it's only set but never read), as well as moving the "is GC locker active" test earlier into the G1 pause / Full GC and using a more appropriate method for it.
Reviewed-by: johnc, jmasa, jcoomes, ysr

Summary: Calling the methods region_stack_push() and region_stack_pop() concurrent is not MT-safe. The assumption is that we will only call region_stack_push() during a GC pause and region_stack_pop() during marking. Unfortunately, we also call region_stack_push() during marking which seems to be introducing subtle marking failures. This change introduces lock-based methods for pushing / popping to be called during marking.
Reviewed-by: iveresov, johnc

Summary: Enable parallel RSet updating and scanning.
Reviewed-by: iveresov, jmasa

Summary: Remove the G1GCPercent parameter, that specifies the desired GC overhead percentage in G1, and observe the GCTimeRatio parameter instead.
Reviewed-by: jmasa, johnc

Summary: process one item at a time from the objarray stack/queue
Reviewed-by: apetrusenko, tonyp

Summary: Newly-created threads always had the active field of their SATB queue initialized to false, even if they were created during marking. As a result, updates from threads created during a marking cycle were never enqueued and never processed. The fix includes remaining a method from active() to is_active() for readability and naming consistency.
Reviewed-by: ysr, johnc

Summary: If CM task was aborted while scanning the last object of the specified region and the size of that object is equal to bitmap's granularity then the next offset would be equal or over the region limit which is exactly what the assertion states.
Reviewed-by: ysr, tonyp, jmasa

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: Calculation of the slicing of survivor spaces for MT was incorrect.
Reviewed-by: ysr

Summary: see synopsis
Reviewed-by: johnc, jmasa

Summary: Rename marking stack sizing flags to be common between G1 and CMS
Reviewed-by: ysr, tonyp

Summary: replace the combination of the G1SteadyStateUsed / G1SteadyStateUsedDelta parameteres to decide the marking initiation threshold and instead use InitiatingHeapOccupancyPercent.
Reviewed-by: ysr, johnc

Summary: Rename G1 parameters to make them more consistent.
Reviewed-by: jmasa, johnc

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: The operations of re-using a RSet component and expanding the same RSet component were not mutually exlusive, and this could lead to RSets getting corrupted and entries being dropped.
Reviewed-by: iveresov, johnc

Summary: Invalid assert. Filter cards evicted from the card count cache instead.
Reviewed-by: apetrusenko, tonyp

Summary: Fixed missing pre-barrier calls for G1, modified C1 to call pre- and correct post-barrier interfaces, deleted obsolete interface, (temporarily) disabled redundant deferred barrier in BacktraceBuilder.
Reviewed-by: coleenp, jmasa, kvn, never

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: Adjust assertion checking for ExplicitGCInvokesConcurrentAndUnloadsClasses as a reason for class unloading
Reviewed-by: ysr

Summary: When enqueuing a completed PtrQueue buffer, cache a local pointer to the buffer and clear the field in the PtrQueue prior to unlocking the mutex referenced by the _lock field and pass the cached local value to the enqueuing routine. This will prevent the same completed buffer being enqueued multiple times, which causes the hang.
Reviewed-by: ysr

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: Block too small to split was not correctly putback to free lists.
Reviewed-by: ysr

Summary: 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

Summary: Reworked the concurrent refinement: threads activation, feedback-based threshold adjustment, other miscellaneous fixes.
Reviewed-by: apetrusenko, tonyp

Summary: Change CollectionSetChooser::printSortedHeapRegions to handle null entries in _markedRegions growable array.
Reviewed-by: jmasa, tonyp, iveresov

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

Summary: Fixes a race on the dirty card queue completed buffer list between worker thread(s) performing a flush of a deferred store barrier (enqueueing a newly completed buffer) and worker thread(s) in the RSet updating code claiming completed buffers. Removed the routine that removes elements from the completed update buffer queue using a CAS.
Reviewed-by: ysr, tonyp

Summary: It introduces the necessary memory pools for G1.
Reviewed-by: mchung, ysr

Summary: ScavengeALot now causes an incremental (but possibly partially young, in the G1 sense) collection. Some such collections may be abandoned on account of MMU specs. Band-aided a native leak associated with abandoned pauses, as well as an MMU tracker overflow related to frequent scavenge events in the face of a large MMU denominator interval; the latter is protected by a product flag that defaults to false.
Reviewed-by: tonyp

Summary: Protected stats dump with a new develop flag; other than for the dump, reconciled product and non-product behaviour in face of the error.
Reviewed-by: tonyp

Summary: Added instrumentation and (temporary) assert in non-product mode; clipped the value when found out-of-bounds in product mode. Fix of original issue will follow collection of data from this instrumentation.
Reviewed-by: jcoomes, tonyp

Summary: Use CollectorPolicy information instead of MaxNewSize
Reviewed-by: ysr, jcoomes

Summary: The type in the NEW_C_HEAP_ARRRY and FREE_C_HEAP_ARRAY calls in the buffer allocation code was changed from void* to char as the size argument had already been mulitipled by the byte size of an object pointer.
Reviewed-by: ysr, tonyp

Summary: Apply modification of existing server heap size ergo to all collectors except CMS.
Reviewed-by: jmasa, ysr, xlu

Summary: The fix addresses two memory leaks in G1 code: (1) _evac_failure_scan_stack - a resource object allocated on the C heap was not freed; (2) RSHashTable were linked into deleted list which was only cleared at full GC.
Reviewed-by: tonyp, iveresov

Reviewed-by: tonyp, ysr

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