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   7  * under the terms of the GNU General Public License version 2 only, as
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  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
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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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  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.
  87 define_pd_global(bool, UseLargePages, false);
  88 define_pd_global(bool, UseLargePagesIndividualAllocation, false);
  89 define_pd_global(bool, UseOSErrorReporting, false);
  90 define_pd_global(bool, UseThreadPriorities, true) ;
  91 
  92 #endif // OS_AIX_VM_GLOBALS_AIX_HPP