8007074: SIGSEGV at ParMarkBitMap::verify_clear() Summary: Replace the broken large pages implementation on Linux. New flag: -XX:+UseTransparentHugePages - Linux specific flag to turn on transparent huge page hinting with madvise(..., MAP_HUGETLB). Changed behavior: -XX:+UseLargePages - tries to use -XX:+UseTransparentHugePages before trying other large pages implementations (on Linux). Changed behavior: -XX:+UseHugeTLBFS - Use upfront allocation of Large Pages instead of using the broken implementation to dynamically committing large pages. Changed behavior: -XX:LargePageSizeInBytes - Turned off the ability to use this flag on Linux and provides warning to user if set to a value different than the OS chosen large page size. Changed behavior: Setting no large page size - Now defaults to use -XX:UseTransparentHugePages if the OS supports it. Previously, -XX:+UseHugeTLBFS was chosen if the OS was configured to use large pages. Reviewed-by: tschatzl, dcubed, brutisso

--- a/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp	Sun Aug 25 21:21:18 2013 -0400
+++ b/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp	Fri Aug 16 13:22:32 2013 +0200
@@ -313,7 +313,8 @@
 void G1CollectorPolicy::initialize_flags() {
   set_min_alignment(HeapRegion::GrainBytes);
   size_t card_table_alignment = GenRemSet::max_alignment_constraint(rem_set_name());
-  set_max_alignment(MAX2(card_table_alignment, min_alignment()));
+  size_t page_size = UseLargePages ? os::large_page_size() : os::vm_page_size();
+  set_max_alignment(MAX3(card_table_alignment, min_alignment(), page_size));
   if (SurvivorRatio < 1) {
     vm_exit_during_initialization("Invalid survivor ratio specified");
   }