rusage_hires_enable.5 (2011 03)

r
rusage_hires_enable(5) rusage_hires_enable(5)
(Tunable Kernel Parameters)
NAME
rusage_hires_enable - enable finer resolution rusage
VALUES
Failsafe
0
Default
0
Allowed values
0 and 1
Recommended value
0
DESCRIPTION
rusage_hires_enable
is a dynamic tunable that determines the resolution of the usage statistics
returned from the getrusage (2), wait3 (2) and wait4(2) system calls. When set to 0, usage statistics are
rounded to 10 msec resolution for compatibility with times (2) and older applications that assumed these
interfaces reported to this resolution. When set to 1, usage statistics are rounded to 1 usec resolution.
Who is Expected to Change This Tunable?
System administrators who need higher than default resolution for rusage statistics may change this tun-
able value.
Restrictions on Changing
None. This tunable is dynamic.
When Should the Value of This Tunable Be Set?
The value of
rusage_hires_enable
should be set to 1 when users require results from rusage calls
(mentioned above) with finer resolution than default (10 msec).
What Are the Side Effects of Setting the Value?
Normal variations in execution time will be more apparent. Older applications that assume these inter-
faces return values with 10 msec resolution may behave unpredictably. Values returned from these inter-
faces will no longer match those returned from times (2) or pstat_getproc(2) in the
pst_utime and
pst_stime fields.
When Should the Value of This Tunable Be Reset?
When older applications are used which expect the usage information to have 10msec resolution.
What Are the Side Effects of Resetting the Value?
None.
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
rusage_hires_enable was developed by HP.
HP-UX 11i Version 3: March 2011 − 1 − Hewlett-Packard Company 1