Summary: Add a WhiteBox callback to the VM to start a concurrent mark cycle in G1.
Reviewed-by: tschatzl, sjohanss
Contributed-by: NLeonid Mesnik <leonid.mesnik@oracle.com>

Reviewed-by: mgerdin, vlivanov

Reviewed-by: jwilhelm, jmasa

Summary: Fix up GPL headers so that the RE script works.
Reviewed-by: stefank, dholmes, coleenp

8061715: gc/g1/TestShrinkAuxiliaryData15.java fails with java.lang.RuntimeException: heap decommit failed - after > before
Summary: added WhiteBox methods to count regions and exact aux data sizes
Reviewed-by: jwilhelm, brutisso

Summary: Don't assume SATB buffer entries are valid objects
Reviewed-by: brutisso, ecaspole

Summary: Removed no longer valid checking of SATB buffers
Reviewed-by: jmasa, pliden

Summary: Apply closure directly, eliminating registration.
Reviewed-by: stefank, tschatzl

Summary: Removed pre-filter verify, and made filtering more careful.
Reviewed-by: brutisso, tschatzl

Summary: Prevent eager reclaim of objects that might be on mark stack.
Reviewed-by: brutisso, tschatzl

Summary: Eliminate _CHECK_BOTH_FINGERS_ and simplify.
Reviewed-by: brutisso, tschatzl

Reviewed-by: tschatzl, ecaspole

Summary: Print selected page size, not alignment size chosen by ReservedSpace (which is the vm_allocation_granularity that is different to page size on Windows) in the message presented by TracePageSizes.
Reviewed-by: drwhite, jmasa

Summary: Allow use of large pages for auxiliary data structures in G1. Clean up existing interfaces.
Reviewed-by: jmasa, pliden, stefank

Summary: Added a guard of gc workers > 0 to execute logic.
Reviewed-by: stefank, mgerdin

8062063: Usage of UseHugeTLBFS, UseLargePagesInMetaspace and huge SurvivorAlignmentInBytes cause crashes in CMBitMapClosure::do_bit
Summary: Making sure committed memory is cleared when re-committed, even if using large pages.
Reviewed-by: jwilhelm, tschatzl

8062063: Usage of UseHugeTLBFS, UseLargePagesInMetaspace and huge SurvivorAlignmentInBytes cause crashes in CMBitMapClosure::do_bit
Summary: Making sure committed memory is cleared when re-committed, even if using large pages.
Reviewed-by: jwilhelm, tschatzl

Summary: Push the remembered sets of large objects with few referenced into the dirty card queue at the beginning of the evacuation so that they may end up with zero remembered set entries at the end of the collection, and are potentially reclaimed. Also improve timing measurements of the early reclaim mechanism, and shorten flag names.
Reviewed-by: brutisso, jmasa, dfazunen

8075210: Refactor strong root processing in order to allow G1 to evolve separately from GenCollectedHeap
Summary: Create a G1RootProcessor and move SharedHeap root processing to GenCollectedHeap
Reviewed-by: brutisso, tschatzl, ehelin

Reviewed-by: tschatzl, mgerdin, ecaspole

8075210: Refactor strong root processing in order to allow G1 to evolve separately from GenCollectedHeap
Summary: Create a G1RootProcessor and move SharedHeap root processing to GenCollectedHeap
Reviewed-by: brutisso, tschatzl, ehelin

Reviewed-by: tschatzl, mgerdin, ecaspole

Summary: Moved allocation context update from remark to the cleanup phase.
Reviewed-by: mgerdin, jmasa

Summary: Added a G1CollectorPolicyExt where it is possible to extend the class.
Reviewed-by: sjohanss, tschatzl

Summary: Read _top before _gc_time_stamp in saved_mark_word() with LoadLoad order to ensure we get a consistent view
Reviewed-by: brutisso, dcubed, dholmes, stefank

8062036: ConcurrentMarkThread::slt may be invoked before ConcurrentMarkThread::makeSurrogateLockerThread causing intermittent crashes
Summary: Suppress gc_alot during VM init, improve error for SLT uninitialized.
Reviewed-by: jmasa, brutisso, tschatzl

8064556: G1: ParallelGCThreads=0 may cause assert(!MetadataOnStackMark::has_buffer_for_thread(Thread::current())) failed: Should be empty
Reviewed-by: mgerdin, tschatzl

Reviewed-by: mgerdin, brutisso

Reviewed-by: mgerdin, brutisso

Reviewed-by: mgerdin, coleenp, bdelsart

8052172: Evacuation failure handling in G1 does not evacuate all objects if -XX:-G1DeferredRSUpdate is set
Summary: Remove -XX:-G1DeferredRSUpdate functionality as it is racy. During evacuation failure handling, threads where evacuation failure handling occurred may try to add remembered sets to regions which remembered sets are currently being scanned. The iterator to handle the remembered set scan does not support addition of entries during scan and so may skip valid references.
Reviewed-by: iveresov, brutisso, mgerdin

Summary: Ergonomics updates flags for number of GC threads
Reviewed-by: tschatzl, jwilhelm
Contributed-by: sangheon.kim@oracle.com

Reviewed-by: brutisso, tschatzl

Summary: Enable yc to be forced for stat update.
Reviewed-by: mgerdin, jcoomes

Reviewed-by: tschatzl, stefank

Reviewed-by: brutisso, jwilhelm

Summary: Replace G1CodeRootSet with a Hashtable based implementation, merge Code Root Migration phase into Code Root Scanning
Reviewed-by: jmasa, brutisso, tschatzl

Summary: Splitting out a g1 allocator class to simply specialized allocators which can associate each allocation with a given context.
Reviewed-by: mgerdin, brutisso

8055635: Missing include in g1RegionToSpaceMapper.hpp results in unresolved symbol of fastdebug build without precompiled headers
Reviewed-by: mgerdin, ehelin

Summary: If large pages are enabled and configured in Linux, the VM always pre-commits the entire space. The VM fails verification of the commit of the initial heap because some internal data structure marked all memory pages of the heap as committed during initialization. This makes the code think that we attempted a double-commit during first allocation of the heap. Remove the initial marking of memory pages of the heap to committed.
Reviewed-by: mgerdin