globals_aix.hpp revision 10049:73443d24e529 
1/*
2 * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
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4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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6 * This code is free software; you can redistribute it and/or modify it
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8 * published by the Free Software Foundation.
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10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
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18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
25
26#ifndef OS_AIX_VM_GLOBALS_AIX_HPP
27#define OS_AIX_VM_GLOBALS_AIX_HPP
28
29//
30// Defines Aix specific flags. They are not available on other platforms.
31//
32// (Please keep the switches sorted alphabetically.)
33#define RUNTIME_OS_FLAGS(develop, develop_pd, product, product_pd, diagnostic, notproduct, range, constraint) \
34                                                                                    \
35  /* Whether to allow the VM to run if EXTSHM=ON. EXTSHM is an environment */       \
36  /* variable used on AIX to activate certain hacks which allow more shm segments */\
37  /* for 32bit processes. For 64bit processes, it is pointless and may have */      \
38  /* harmful side effects (e.g. for some reasonn prevents allocation of 64k pages */\
39  /* via shmctl). */                                                                \
40  /* Per default we quit with an error if that variable is found; for certain */    \
41  /* customer scenarios, we may want to be able to run despite that variable. */    \
42  product(bool, AllowExtshm, false,                                                 \
43          "Allow VM to run with EXTSHM=ON.")                                        \
44                                                                                    \
45  product(intx, AttachListenerTimeout, 1000,                                        \
46          "Timeout in ms the attach listener waits for a request")                  \
47          range(0, 2147483)                                                         \
48                                                                                    \
49  /*  Maximum expected size of the data segment. That correlates with the      */   \
50  /*  to the maximum C Heap consumption we expect.                             */   \
51  /*  We need to know this because we need to leave "breathing space" for the  */   \
52  /*  data segment when placing the java heap. If that space is too small, we  */   \
53  /*  reduce our chance of getting a low heap address (needed for compressed   */   \
54  /*  Oops).                                                                   */   \
55  product(uintx, MaxExpectedDataSegmentSize, (SIZE_4G * 2),                         \
56          "Maximum expected Data Segment Size.")                                    \
57                                                                                    \
58  /* Use optimized addresses for the polling page.                             */   \
59  product(bool, OptimizePollingPageLocation, true,                                  \
60             "Optimize the location of the polling page used for Safepoints")       \
61                                                                                    \
62  /* Use 64K pages for virtual memory (shmat). */                                   \
63  product(bool, Use64KPages, true,                                                  \
64          "Use 64K pages if available.")                                            \
65                                                                                    \
66  /*  If VM uses 64K paged memory (shmat) for virtual memory: threshold below  */   \
67  /*  which virtual memory allocations are done with 4K memory (mmap). This is */   \
68  /*  mainly for test purposes.                                                */   \
69  develop(uintx, Use64KPagesThreshold, 0,                                           \
70          "4K/64K page allocation threshold.")                                      \
71                                                                                    \
72  /* Normally AIX commits memory on touch, but sometimes it is helpful to have */   \
73  /* explicit commit behaviour. This flag, if true, causes the VM to touch     */   \
74  /* memory on os::commit_memory() (which normally is a noop).                 */   \
75  product(bool, UseExplicitCommit, false,                                           \
76          "Explicit commit for virtual memory.")                                    \
77                                                                                    \
78
79
80//
81// Defines Aix-specific default values. The flags are available on all
82// platforms, but they may have different default values on other platforms.
83//
84
85// UseLargePages means nothing, for now, on AIX.
86// Use Use64KPages or Use16MPages instead.
87define_pd_global(bool, UseLargePages, false);
88define_pd_global(bool, UseLargePagesIndividualAllocation, false);
89define_pd_global(bool, UseOSErrorReporting, false);
90define_pd_global(bool, UseThreadPriorities, true) ;
91
92#endif // OS_AIX_VM_GLOBALS_AIX_HPP
93