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
OPENJDK ASSEMBLY EXCEPTION
The OpenJDK source code made available by Sun at openjdk.java.net and
openjdk.dev.java.net ("OpenJDK Code") is distributed under the terms of the
GNU General Public License <http://www.gnu.org/copyleft/gpl.html> version 2
only ("GPL2"), with the following clarification and special exception.
Linking this OpenJDK Code statically or dynamically with other code
is making a combined work based on this library. Thus, the terms
and conditions of GPL2 cover the whole combination.
As a special exception, Sun gives you permission to link this
OpenJDK Code with certain code licensed by Sun as indicated at
http://openjdk.java.net/legal/exception-modules-2007-05-08.html
("Designated Exception Modules") to produce an executable,
regardless of the license terms of the Designated Exception Modules,
and to copy and distribute the resulting executable under GPL2,
provided that the Designated Exception Modules continue to be
governed by the licenses under which they were offered by Sun.
As such, it allows licensees and sublicensees of Sun's GPL2 OpenJDK Code to
build an executable that includes those portions of necessary code that Sun
could not provide under GPL2 (or that Sun has provided under GPL2 with the
Classpath exception). If you modify or add to the OpenJDK code, that new
GPL2 code may still be combined with Designated Exception Modules if the
new code is made subject to this exception by its copyright holder.