dispadmin(1M) System Administration Commands dispadmin(1M)
NAME
dispadmin - process scheduler administration
SYNOPSIS
dispadmin -l
dispadmin -c class -g [-r res]
dispadmin -d [class]
DESCRIPTION
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: Basic Administration
OPTIONS
The following options are supported:
-c class 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, IA for the inter-active class, FSS for the fair-share class, and FX for the fixed-priority
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.
-d [class] Sets or displays the name of the default scheduling class to be used on reboot by the startup script /etc/init.d/sysetup.
If class name is not specified, the name and description of the current default scheduling class is displayed. If class
name is specified and is a valid scheduling class name, then it is saved in dispadmin's private configuration file
/etc/dispadmin.conf. Only super-users can set the default scheduling class.
-g 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). Parameters
for the fair-share class are described in FSS(7). Parameters for the fixed-priority class are described in fx_dptbl(4).
The -g and -s options are mutually exclusive: you may not retrieve the table at the same time you are overwriting it.
-l Lists the scheduler classes currently configured in the system.
-r res 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.
-s file 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.
Specify time quantum values for scheduling classes in system clock ticks, and not in constant-time units. Time quantum
values are based on the value of the kernel's hz variable. If kernel variable hires_tick is set to 1 to get higher resolu-
tion clock behavior, the actual time quanta will be reduced by the order of 10.
The -g and -s options are mutually exclusive: you may not retrieve the table at the same time you are overwriting it.
EXAMPLES
Example 1: Retrieving the Current Scheduler Parameters for the real-time class
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
Example 2: Overwriting the Current Scheduler Parameters for the Real-time Class
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
Example 3: Retrieving the Current Scheduler Parameters for the Time-sharing Class
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
Example 4: Overwriting the Current Scheduler Parameters for the Time-sharing Class
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
FILES
/etc/dispadmin.conf
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO
priocntl(1), priocntl(2), fx_dptbl(4), rt_dptbl(4), ts_dptbl(4), attributes(5), FSS(7)
System Administration Guide: Basic Administration Programming Interfaces Guide
DIAGNOSTICS
dispadmin prints an appropriate diagnostic message if it fails to overwrite the current scheduler parameters due to lack of required per-
missions or a problem with the specified input file.
SunOS 5.10 7 Oct 2002 dispadmin(1M)