8007074: SIGSEGV at ParMarkBitMap::verify_clear()

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

hotspot/src/share/vm/memory/collectorPolicy.cpp

@@ -193,6 +193,8 @@ size_t GenCollectorPolicy::compute_max_alignment() {
       alignment = lcm(os::large_page_size(), alignment);
   }
 
+  assert(alignment >= min_alignment(), "Must be");
+
   return alignment;
 }