Summary: Move the first part of the GC logging, including timestamp, to the start of the GC
Reviewed-by: johnc, jwilhelm

Reviewed-by: brutisso, johnc, ysr
Contributed-by: NHal Mo <kungu.mjh@taobao.com>

Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: Njmasa &lt;jon.masamitsu@oracle.com&gt;, stefank &lt;stefan.karlsson@oracle.com&gt;, mgerdin &lt;mikael.gerdin@oracle.com&gt;, never <tom.rodriguez@oracle.com>

Summary: Add the flags G1EvacuationFailureALot flag (and supporting flags) to force trigger evacuation failures. The support flags control how often to trigger an evacuation failure and during which types of evacuation pause. This functionality is analogous to that of PromotionFailureALot for the other collectors.
Reviewed-by: brutisso

7178363: G1: Remove the serial code for PrintGCDetails and make it a special case of the parallel code
Summary: Also reviewed by vitalyd@gmail.com. Introduced the WorkerDataArray class. Fixed some minor logging bugs.
Reviewed-by: johnc, mgerdin

Summary: Also reviewed by: vitalyd@gmail.com. Make G1DefaultMinNewGenPercent, G1DefaultMaxNewGenPercent, G1OldCSetRegionLiveThresholdPercent and G1OldCSetRegionThresholdPercent experimental flags
Reviewed-by: ysr, johnc, jmasa

Summary: Correct the result value of G1CollectedHeap::pending_card_num(). Change the code that calculates the GC efficiency of a non-young heap region to use historical data from mixed GCs and the actual number of live bytes when predicting how long it would take to collect the region. Changes were also reviewed by Thomas Schatzl.
Reviewed-by: azeemj, brutisso

Summary: G1 does not appear to be immune to the issue described in CR 6948537 and increasing the size of old-generation PLABs appears to increase the liklihood of seeing the issue. Extend the fix for 6948537 to G1's BlockOffsetTable.
Reviewed-by: brutisso, jmasa

Summary: Employ PLABStats instances to record information about survivor and old PLABs, and use the recorded stats to adjust the sizes of survivor and old PLABS.
Reviewed-by: johnc, ysr
Contributed-by: NBrandon Mitchell <brandon@twitter.com>

Summary: Various cleanups as a prelude to introducing iterators for HeapRegions.
Reviewed-by: johnc, brutisso

Summary: Chain the fine grain PerRegionTables in an individual RSet together and free them in bulk using a single operation.
Reviewed-by: johnc, brutisso
Contributed-by: NThomas Schatzl <thomas.schatzl@jku.at>

Summary: Assertion incorrectly checks that _head is NULL and should be checking that _tail is NULL instead.
Reviewed-by: johnc
Contributed-by: NBrandon Mitchell <brandon@twitter.com>

Summary: Duplicated code from G1RemSet::par_write_ref() inlined into G1UpdateRSOrPushRefOopClosure::do_oop_nv() was showing up in profiles with a fairly high amount of CPU time. Manually inline the main part of G1RemSet::par_write_ref() to eliminate the code duplication.
Reviewed-by: azeemj, brutisso

Summary: Also reviewed by: vitalyd@gmail.com. Move the timing out of G1CollectorPolicy into the G1GCPhaseTimes class
Reviewed-by: johnc

7151532: DCmd for hotspot native memory tracking
Summary: Implementation of native memory tracking phase 1, which tracks VM native memory usage, and related DCmd
Reviewed-by: acorn, coleenp, fparain

Summary: Remove the per-thread expansion tables (PosParPRT) and associated expansion and compaction from the fine grain RSet entries. This code has been unused for a while.
Reviewed-by: johnc, brutisso
Contributed-by: NThomas Schatzl <thomas.schatzl@jku.at>

Summary: The scope of TraceMemoryManagerStats in G1CollectedHeap need to cover the call to G1MonitoringSupport::update_sizes()
Reviewed-by: johnc, jmasa

Reviewed-by: azeemj, jmasa

Summary: Simplify code, remove unused code, remove ExitAfterGCNum
Reviewed-by: huntch, johnc

Summary: Removed LOG_G and LOG_K. Moved LOG_M to where it is being used.
Reviewed-by: twisti, johnc

Summary: Before the last thread to leave a JNI critical region was able to schedule a GCLocker Initiated GC, another thread was attempting an allocation and saw that the GCLocker region was no longer active and successfully scheduled a GC. Stall allocating threads until the GCLocker Initiated GC is performed and then retry the allocation.
Reviewed-by: brutisso, huntch

Reviewed-by: mgerdin, johnc

Summary: GC cause was not being set by the VM_G1CollectForAllocation VM operation.
Reviewed-by: jmasa, ysr, brutisso

Summary: Rename "to-space-overflow" to "to-space-exhausted", Introduce one decimal point in the size format, Add Sum to the aggregate and re-order the entries, Add number of GC workers to the log output
Reviewed-by: johnc, jwilhelm

Reviewed-by: johnc, jwilhelm, jmasa

Summary: Removed the HeapRegion::_top_at_conc_mark_count field. It is no longer needed as a result of the changes for 6888336 and 7127706. Refactored the closures that finalize and verify the liveness counting data so that common functionality was placed into a base class.
Reviewed-by: brutisso, tonyp

Summary: Cleanup of the CSet chooser class: standardize on uints for region num and indexes (instead of int, jint, etc.), make the method / field naming style more consistent, remove a lot of dead code.
Reviewed-by: johnc, brutisso

Summary: Change the type of fields / variables / etc. that represent region counts and indeces from size_t to uint.
Reviewed-by: iveresov, brutisso, jmasa, jwilhelm

Summary: removed oop_verify_old_oop and allow_dirty. Also reviewed by: alexlamsl@gmail.com
Reviewed-by: jmasa, jwilhelm

Summary: Added log levels "fine", "finer" and "finest". Let PrintGC map to "fine" and PrintGCDetails map to "finer". Separated out the per worker information in the G1 logging to the "finest" level.
Reviewed-by: stefank, jwilhelm, tonyp, johnc

Summary: Removed lots of dead code after some recent conc mark changes.
Reviewed-by: brutisso, johnc

Summary: Some minor cleanups
Reviewed-by: tonyp, jwilhelm

Summary: Make two G1 cmd line flags available in product builds: G1HeapWastePercent (previously called: G1OldReclaimableThresholdPercent) and G1MixedGCCountTarget (previous called: G1MaxMixedGCNum). Also changed the default of the former from 1% to 5% and the default for G1OldCSetRegionLiveThresholdPercent to 90%.
Reviewed-by: azeemj, jwilhelm, johnc

Reviewed-by: tonyp, johnc

Summary: Add destructor to TruncatedSeq and call delete when necessary
Reviewed-by: johnc, tonyp

Summary: Tiered compilation has increased the number of nmethods in the code cache. This has, in turn, significantly increased the number of marked nmethods processed during the StrongRootsScope destructor. Create a specialized version of CodeBlobToOopClosure for G1 which places only those nmethods that contain pointers into the collection set on to the marked nmethods list.
Reviewed-by: iveresov, tonyp

Summary: Attempting to initiate a marking cycle when allocating a humongous object can, if a marking cycle is successfully initiated by another thread, result in the allocating thread spinning until the marking cycle is complete. Eliminate a deadlock between the main ConcurrentMarkThread, the SurrogateLocker thread, the VM thread, and a mutator thread waiting on the SecondaryFreeList_lock (while free regions are going to become available) by not manipulating the pending list lock during the prologue and epilogue of the cleanup pause.
Reviewed-by: brutisso, jcoomes, tonyp

Summary: Update generation and collector counters only if UsePerfData is enabled.
Reviewed-by: iveresov, tonyp

Summary: Revamp of the mechanism that chooses old regions for inclusion in the CSet. It simplifies the code and introduces min and max bounds on the number of old regions added to the CSet at each mixed GC to avoid pathological cases. It also ensures that when we do a mixed GC we'll always find old regions to add to the CSet (i.e., it eliminates the case where a mixed GC will collect no old regions which can happen today).
Reviewed-by: johnc, brutisso

Reviewed-by: kvn, jrose, kevinw, brutisso, twisti, jmasa