dispadmin(1M) 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, TS for
the time-sharing class, and FP for the fixed-priority 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 in rtdptbl(4). Parameters for the time-sharing class are
described in tsdptbl(4). Parameters for the fixed-priority class are
described in fpdptbl(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
1,000,000,000 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 1,000,000,000
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 reso-
lution.
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 overwritten. 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.
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dispadmin(1M) dispadmin(1M)
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.
EXAMPLES
The following command retrieves the current scheduler parameters for
the real-time class from kernel memory and writes 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 parameters for
the time-sharing class from kernel memory and writes them to the stan-
dard 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 specified in ts.config.
dispadmin -c TS -s ts.config
The following command retrieves the current scheduler parameters for
the fixed-priority class from kernel memory and writes them to the
standard output. Time quantum values are in nanoseconds.
dispadmin -c FP -g -r 1000000000
The following command overwrites the current scheduler parameters for
the fixed-priority class with the values specified in fp.config.
dispadmin -c FP -s fp.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), fpdptbl(4), rtdptbl(4), tsdptbl(4).
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