dispadmin(1M) SYSTEM ADMINISTRATION COMMANDS dispadmin(1M)
NAME
dispadmin - process scheduler administration
SYNOPSIS
dispadmin -l
dispadmin -c class -g [-r res]
dispadmin -c class -s file
DESCRIPTION
The dispadmin command displays or changes process scheduler
parameters while the system is running. The -l option lists
the scheduler classes currently configured in the system.
The -c option specifies the class whose parameters are to be
displayed or changed. Valid class values are RT for the
real-time class and TS for the time-sharing class. The -g
option gets the parameters for the specified class and
writes them to the standard output. Parameters for the
real-time class are described on rtdptbl(4). Parameters
for the time-sharing class are described on tsdptbl(4).
When using the -g option you may also use the -r option to
specify a resolution to be used for outputting the time
quantum values. If no resolution is specified, time quantum
values are in milliseconds. If res is specified it must be
a positive integer between 1 and 1000000000 inclusive, and
the resolution used is the reciprocal of res in seconds.
For example, a res value of 10 yields time quantum values
expressed in tenths of a second; a res value of 1000000
yields time quantum values expressed in microseconds. If
the time quantum cannot be expressed as an integer in the
specified resolution, it is rounded up to the next integral
multiple of the specified resolution. The -s option sets
scheduler parameters for the specified class using the
values in file. These values overwrite the current values
in memory-they become the parameters that control scheduling
of processes in the specified class. The values in file
must be in the format output by the -g option. Moreover,
the values must describe a table that is the same size (has
same number of priority levels) as the table being overwrit-
ten. Super-user privileges are required in order to use the
-s option. The -g and -s options are mutually exclusive:
you may not retrieve the table at the same time you are
overwriting it. dispadmin does some limited sanity checking
on the values supplied in file to verify that they are
within their required bounds. The sanity checking, however,
does not attempt to analyze the effect that the new values
have on the performance of the system. Inappropriate values
can have a dramatic negative effect on system performance.
See the System Administrator's Guide for more information.
EXAMPLES
The following command retrieves the current scheduler param-
eters for the real-time class from kernel memory and writes
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dispadmin(1M) SYSTEM ADMINISTRATION COMMANDS dispadmin(1M)
them to the standard output. Time quantum values are in
microseconds.
dispadmin -c RT -g -r 1000000
The following command overwrites the current scheduler
parameters for the real-time class with the values specified
in rt.config.
dispadmin -c RT -s rt.config
The following command retrieves the current scheduler param-
eters for the time-sharing class from kernel memory and
writes them to the standard output. Time quantum values are
in nanoseconds.
dispadmin -c TS -g -r 1000000000
The following command overwrites the current scheduler
parameters for the time-sharing class with the values speci-
fied in ts.config.
dispadmin -c TS -s ts.config
DIAGNOSTICS
dispadmin prints an appropriate diagnostic message if it
fails to overwrite the current scheduler parameters due to
lack of required permissions or a problem with the specified
input file.
SEE ALSO
priocntl(1), priocntl(2), rt_dptbl(4), ts_dptbl(4)
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