Summary: This changeset removes the zero-filling thread from G1 and collapses the two free region lists we had before (the "free" and "unclean" lists) into one. The new free list uses the new heap region sets / lists abstractions that we'll ultimately use it to keep track of all regions in the heap. A heap region set was also introduced for the humongous regions. Finally, this change increases the concurrency between the thread that completes freeing regions (after a cleanup pause) and the rest of the system (before we'd have to wait for said thread to complete before allocating a new region). The changest also includes a lot of refactoring and code simplification.
Reviewed-by: jcoomes, johnc

Summary: With recent G1 allocation path changes, the value of StackShadowPages in fast debug builds of the JVM, is no longer large enough to prevent the JVM C++ code from touching the stack guard pages. Increase the value of StackShadowPages to a suitable value.
Reviewed-by: ysr, tonyp, coleenp

Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads.
Reviewed-by: johnc, ysr

Summary: Revert a (relaxed version of the) bounds-check that was incorrectly removed in the fix for 7008136.
Reviewed-by: jmasa, johnc

Summary: Pass the value of UseLargePages instead of false as the "large" parameter when reserving the G1 heap.
Reviewed-by: tonyp, johnc, phh

Summary: Make both compilers emit near and far calls when necessary.
Reviewed-by: never, kvn, phh

Summary: Change get_temp_directory() back to /tmp and %TEMP% like it always was and where the tools expect it to be.
Reviewed-by: phh, dcubed, kamg, alanb

Summary: First attempt to allocate out the current alloc region using a CAS instead of taking the Heap_lock (first level of G1's slow allocation path). Only if that fails and it's necessary to replace the current alloc region take the Heap_lock (that's the second level of G1's slow allocation path).
Reviewed-by: johnc, brutisso, ysr

Summary: During evacuation failure handling we refine the BOT to reflect the location of all the objects in the regions we scan. The changeset includes some minor cleanup: a) non-product print_on() method on the G1 BOT class, b) added more complete BOT verification during heap / region verification, c) slight modification to the BOT set up for humongous regions to be more consistent with the BOT set up during evac failure handling, and d) removed a couple of unused methods.
Reviewed-by: johnc, ysr

Reviewed-by: mchung, acorn

Summary: Move _lower_dimension field initialization before _higher_dimension and add storestore barrier.
Reviewed-by: dholmes, iveresov, never

Summary: Replaced incr_allocated_bytes() formals var_size_in_bytes and con_size_in_bytes with a single RegisterOrConstant formal.
Reviewed-by: twisti, jcoomes

Summary: Mark field volatile, use membars, and change access order to close race
Reviewed-by: dcubed, dholmes

Summary: Reuse set_method_data_for_bcp() to setup mdp after MDO creation.
Reviewed-by: kvn, never

Summary: Make JvmtiGCMark safe to run non-safepoint and instrument CMS
Reviewed-by: ysr, dcubed

Reviewed-by: kvn, never

Reviewed-by: never

Summary: Modify membars to match regular volatile variable handling
Reviewed-by: iveresov, kvn, never

Summary: Update the HS20 build number to 06
Reviewed-by: jcoomes

6876037: CTW fails jdk7/hotspot/src/share/vm/opto/type.cpp:2055. assert(bits,"Use TypePtr for NULL")
Summary: Add missing 0 value check in TypeRawPtr::add_offset().
Reviewed-by: never

Summary: Use Atomic::load() and Atomic::store() to access a volatile long.
Reviewed-by: iveresov, jrose, dholmes, never

Summary: Codebuffer can overflow on test with large number of calls
Reviewed-by: dholmes, collins

Summary: Track allocated bytes in Thread's, update on TLAB retirement and direct allocation in Eden and tenured, add JNI methods for ThreadMXBean.
Reviewed-by: coleenp, kvn, dholmes, ysr

Reviewed-by: phh, acorn, kamg

Summary: The recorded _sweep_limit may not necessarily remain a block boundary as the old generation expands during a concurrent cycle. Terminal actions inside the sweep closure need to be aware of this as they cross over the limit.
Reviewed-by: johnc, minqi