The dispadmin command displays or changes process scheduler parameters while the system is running.
dispadmin does limited checking on the values supplied in file to verify that they are within their required bounds. The 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 negative effect on system performance. (See System Administration Guide, Volume 1
Lists the scheduler classes currently configured in the system.
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 IA for the inter-active class. The time-sharing and inter-active classes share the same scheduler, so changes to the scheduling parameters of one will change those of the other.
Gets the parameters for the specified class and writes them to the standard output. Parameters for the real-time class are described in rt_dptbl(4). Parameters for the time-sharing and inter-active classes are described in ts_dptbl(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.
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.
Note: The -g and -s options are mutually exclusive: you may not retrieve the table at the same time you are overwriting it.
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 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 specified in ts.config.
dispadmin -c TS -s ts.config
See attributes(5) for descriptions of the following attributes:
|ATTRIBUTE TYPE||ATTRIBUTE VALUE|
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.