System Tunable Mapping: Tru64 UNIX to HP-UX 11i v2

Virtual Memory Attributes
The following table shows the system tuning options for virtual memory attributes based on HP-UX:
Tru64 UNIX HP-UX Dynamic
on
HP-UX
Description
gh_chunks
N/A
N/A
Number of 4-MB chunks of memory reserved at boot
time for shared-memory use.
rad_gh_regions[n]
N/A
N/A
For NUMA systems, the granularity hints chunk size
(in MB) for the Resource Affinity Domain (RAD)
identified by n.
maxvas (Version 4.0x
only)
N/A
N/A
Maximum Virtual Address Space.
vpagemax (Version 4.0x
only)
N/A
N/A
Maximum Protected Pages.
mapentries (Version
4.0x only)
N/A
N/A
VM maximum map entries.
executable_stack executable_stack
No Controls if the stack is executable (Boolean). The
HP-UX 11i v2 default is 0. The Tru64 UNIX default
is 0.
There are no equivalences on HP-UX for most of Tru64 UNIX vm parameters. For more information on
system attributes for the vm kernel subsystem on Tru64 UNIX, refer to the
sys_attrs_vm(5) reference
page for your version of Tru64 UNIX.
Asynchronous I/O Attributes
The following table shows the system tuning options for asynchronous I/O attributes based on HP-UX:
Tru64 UNIX HP-UX Dynamic on HP-UX Description
aio_listio_max_num aio_listio_max
Yes Maximum number of POSIX asynchronous
I/O operations allowed in a single
lio_listio() call.
aio_max_percent
N/A
N/A
Maximum percentage of physical memory
that AIO structures can occupy.
aio_task_max_num
N/A
N/A
Number of AIO requests that can be wired
in physical memory by restricting the
amount of wired physical memory available
for a specified number of tasks.
aio_listio_max_num (Tru64 UNIX) versus aio_listio_max (HP-UX)
This parameter defines the maximum number of asynchronous I/O requests supported on the list
initiated by the lio_listio() function.
The default value of this parameter is different for Tru64 UNIX and HP-UX. The default setting is 64 for
Tru64 UNIX, and 256 for HP-UX. The maximum value allowed on this parameter is 256 for Tru64
UNIX, the maximum value allowed is 65536 for HP-UX.
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