hotspot/src/os/linux/vm/globals_linux.hpp
author stefank
Fri, 16 Aug 2013 13:22:32 +0200
changeset 19546 f6b7c9e96ea3
parent 15926 8e87d545195f
child 20400 1c658ebcb3c1
permissions -rw-r--r--
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

/*
 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef OS_LINUX_VM_GLOBALS_LINUX_HPP
#define OS_LINUX_VM_GLOBALS_LINUX_HPP

//
// Defines Linux specific flags. They are not available on other platforms.
//
#define RUNTIME_OS_FLAGS(develop, develop_pd, product, product_pd, diagnostic, notproduct) \
  product(bool, UseOprofile, false,                                     \
        "enable support for Oprofile profiler")                         \
                                                                        \
  product(bool, UseLinuxPosixThreadCPUClocks, true,                     \
          "enable fast Linux Posix clocks where available")             \
/*  NB: The default value of UseLinuxPosixThreadCPUClocks may be        \
    overridden in Arguments::parse_each_vm_init_arg.  */                \
                                                                        \
  product(bool, UseHugeTLBFS, false,                                    \
          "Use MAP_HUGETLB for large pages")                            \
                                                                        \
  product(bool, UseTransparentHugePages, false,                         \
          "Use MADV_HUGEPAGE for large pages")                          \
                                                                        \
  product(bool, LoadExecStackDllInVMThread, true,                       \
          "Load DLLs with executable-stack attribute in the VM Thread") \
                                                                        \
  product(bool, UseSHM, false,                                          \
          "Use SYSV shared memory for large pages")

//
// Defines Linux-specific default values. The flags are available on all
// platforms, but they may have different default values on other platforms.
//
define_pd_global(bool, UseLargePages, true);
define_pd_global(bool, UseLargePagesIndividualAllocation, false);
define_pd_global(bool, UseOSErrorReporting, false);
define_pd_global(bool, UseThreadPriorities, true) ;

#endif // OS_LINUX_VM_GLOBALS_LINUX_HPP