hires_timeout_enable.5 (2010 09)

h
hires_timeout_enable(5) hires_timeout_enable(5)
(Tunable Kernel Parameters)
NAME
hires_timeout_enable - enable high resolution timers support
VALUES
Failsafe
0
Default
0
Allowed values
0: disable
1: enable
Recommended values
0 unless applications require high resolution timers.
DESCRIPTION
hires_timeout_enable
is a dynamic tunable that enables/disables support for high resolution timers
and timed sleep for the following Application Programming Interfaces (APIs) -
getitimer(),
nanosleep(), semtimedop(), setitimer(), sigtimedwait()
, timer_gettime(),
timer_settime(), ualarm()
, usleep(), and pthread_cond_timedwait(). With the higher
resolution, these interfaces can be expected to support time intervals less than the current 10 ms.
Who Is Expected to Change This Tunable?
System administrators who need higher than default resolution for applications.
Restrictions on Changing
hires_timeout_enable
changes take effect immediately. However, changes to this tunable will not
affect timed events already queued.
When Should the Value of This Tunable Be Raised?
The value of
hires_timeout_enable
should be set to 1 if applications require higher resolution for
proper operation. Changes will be system-wide.
What Are the Side Effects of Raising the Value?
The number of timer-related interrupts may increase.
When Should the Value of This Tunable Be Lowered?
The value of
hires_timeout_enable
may be set to 0 if there is no longer any overriding need for
higher than default resolution.
What Are the Side Effects of Lowering the Value?
Fewer timer-related interrupts.
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
hires_timeout_enable was developed by HP.
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1