Reviewed-by: pbk, kvn

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: With Zero on a GC crash the stack was dumped differently to other crashes.
Reviewed-by: twisti
Contributed-by: NGary Benson <gbenson@redhat.com>

Summary: ensure_parsability() must be called even if GC_locker prevents GC.
Reviewed-by: ysr, chrisphi

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

Reviewed-by: twisti

Summary: The outgoing region map is not maintained properly and it's causing an assert failure. Given that we don't actually use it, I'm removing it. I'm piggy-backing a small change on this which removes a message that it's printed before a Full GC when DisableExplicitGC is set.
Reviewed-by: apetrusenko, ysr

Summary: The expression that calculates the live bytes for a heap region can overflow for a suitably large humongous region/object. Cache the object size in a suitably sized local variable so that the expression is converted to a wider type.
Reviewed-by: tonyp, jmasa, iveresov, apetrusenko

Summary: Adding stack overflow checking to Shark brought to light a bunch of deficiencies in Zero's stack overflow code.
Reviewed-by: twisti
Contributed-by: NGary Benson <gbenson@redhat.com>

Reviewed-by: twisti

Summary: This fixes lir_cmp_l2i on x64 and sparc 64bit, and the debug info generation.
Reviewed-by: never

6941529: SharedRuntime::raw_exception_handler_for_return_address must reset thread MethodHandle flag
Summary: During testing a bug was hit when an exception returned to the interpreter and the SP was wrong.
Reviewed-by: kvn, never

Summary: Use BIS instruction for allocation prefetch on Sparc
Reviewed-by: twisti

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: Use FieldsAllocationStyle=2 to allocate non static oop fields in super and sub classes together
Reviewed-by: twisti

Summary: Don't align loops in stubs for Niagara sparc since NOPs are expensive.
Reviewed-by: twisti, never

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: ScavengeRootsInCode can lead to unfixed code-embedded oops.
Reviewed-by: kvn, never

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: Fix typo.
Reviewed-by: never

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

Reviewed-by: kvn

Summary: Get java.io.tmpdir property in os::get_temp_directory() and call this instead of harcoding "/tmp".  Don't assume trailing file_separator either.
Reviewed-by: dholmes, kamg

Reviewed-by: never
Contributed-by: ed@camswl.com

Summary: Various fixes to the G1 debugging output.
Reviewed-by: johnc, iveresov

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

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: Remove assert to decouple JDK and HotSpot additions of known types.
Reviewed-by: mchung

Reviewed-by: twisti

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: Some code cleanups found during the JSR 292 SPARC port.
Reviewed-by: kvn, never

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

Reviewed-by: kvn

Summary: Adding probes related to thread scheduling and class initialization
Reviewed-by: kamg, never

Summary: The logic for x86 C1 to save the SP over MH calls is pretty straight forward but SPARC handles that differently.
Reviewed-by: never, jrose

Summary: Add missing guard.
Reviewed-by: never

Summary: Passing a null pointer to an InvokeDynamic function call should lead to a NullPointerException.
Reviewed-by: kvn, never

Summary: Restore code deleted in 6626217
Reviewed-by: asaha, kevinw

Summary: Use -XX:+TraceSafepointCleanupTime to print out the details of each clean up tasks.
Reviewed-by: dholmes, ysr