Don't turn on transparent huge pages (-XX:+UseTransparentHugePages) unless explicitly specified on the command line. This has the effect that large pages are never turned on Linux unless the user has explicitly enabled any of the large pages flags: -XX:+UseLargePages, -XX:+UseTransparentHugePages, -XX:+UseHugeTLBFS, and -XX:+UseSHM.
Reviewed-by: jwilhelm, tschatzl, brutisso
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
