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rtsched_numpri.5 (2010 09)

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rtsched_numpri(5) rtsched_numpri(5)
(Tunable Kernel Parameters)
NAME
rtsched_numpri - number of priority values to support for POSIX.1b realtime applications
VALUES
Failsafe
32
Default
32
Allowed Values
Any value in the range of 32 to
512 is allowed. A value lower than 32 is reset to 32, whereas a value
higher than
512 is reset to 512
.
Recommended Value
32
DESCRIPTION
The rtsched_numpri
tunable defines how many priority values to support for POSIX 1.b realtime
applications. A larger value provides additional flexibility to applications in managing relative priorities
of all threads with respect to each other and with respect to other applications running in the system.
However, a larger value adds processing overhead in the operating system in terms of managing larger
run queues with the possibility of increased search times.
Who Is Expected to Change This Tunable?
Anyone.
Restrictions on Changing
Changes to this tunable take effect at next reboot.
When Should the Value of This Tunable Be Raised?
When the system is primarily running POSIX realtime applications, and requires additional flexibility in
managing relative priorities of applications.
What Are the Side Effects of Raising the Value?
Raising the value of the
rtsched_numpri
tunable may cause some operating system overhead due to
larger and possibly more sparse run queues.
When Should the Value of This Tunable Be Lowered?
The default value of the
rtsched_numpri
tunable is already set to the minimum possible value.
What Other Tunable Values Should Be Changed at the Same Time?
None.
WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its
meaning changed in future releases of HP-UX.
Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parame-
ter values. After installation, some tunable parameters may no longer be at the default or recommended
values. For information about the effects of installation on tunable values, consult the documentation for
the kernel software being installed. For information about optional kernel software that was factory
installed on your system, see HP-UX Release Notes at
http://www.hp.com/go/hpux-core-docs
.
AUTHOR
rtsched_numpri was developed by HP.
SEE ALSO
kctune(1M).
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1

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