6977804: G1: remove the zero-filling thread 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

Merge

7012642: G1: JumbleGC002 test aborts with segmentation violation due to uncaught stack overflow 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

7011379: G1: overly long concurrent marking cycles 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

Merge

7012505: BreakpointWithFullGC.sh fails with Internal Error (src/share/vm/oops/methodOop.cpp:220) Summary: Rebuild breakpoint cache at gc_epilogue instead of during oops_do Reviewed-by: dcubed, ysr, coleenp

7013008: 2/3 assert(method == NULL || check_method(method, bcp)) failed: bcp must point into method Summary: The Relocator should pass a NULL methodOop when rewriting since its resource array can never contain breakpoints. Reviewed-by: dcubed, kvn, coleenp

7012493: 2/2 6849574/Test.java fails with Internal Error (src/share/vm/prims/jvmtiTagMap.cpp:3294) Summary: Refine assertion to work before VMThread has started. Reviewed-by: ysr, never, dholmes, acorn

Merge

6811367: Fix code in HeapDumper::dump_heap() to avoid buffer overrun Summary: Check buffer size before using and use dynamic buffer sizes for subsequent calls. Reviewed-by: kamg, dholmes