7040485: Use transparent huge page on linux by default
Summary: Turn on UseLargePages by default but try only HugeTLBFS method if it is not explicitly specified on the command line.
Reviewed-by: ysr
/*
* Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* 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).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 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, 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