dispadmin - process scheduler administration
dispadmin -l
dispadmin -c class {-g [-r res] | -s file}
dispadmin -d [class]
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: Advanced Administration.)
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 when starting svc:/system/scheduler:default. 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(5). Parameters for the time-sharing and inter-active
classes are described in
ts_dptbl(5). Parameters for the fair-share
class are described in
FSS(4). Parameters for the fixed-priority class
are described in
fx_dptbl(5).
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.
Time quantum values for scheduling classes are specified in system
clock ticks rather than constant-time units. These values are based on the
value of the kernel's hz variable. By default, the system operates at
1000 Hz and thus with a quantum of 1 millisecond. If the kernel tunable
hires_tick is set to 0, this drops to 100 Hz for a larger quantum of
10 milliseconds.
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
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
standard 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
/etc/dispadmin.conf
Possible location for argument to -s option.
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.
The default scheduling class setting facility is managed by the service
management facility, smf(7), under the service identifier:
svc:/system/scheduler:default
Administrative actions on this service, such as enabling,
disabling, or requesting restart, can be performed using svcadm(8).
Note that disabling the service while it is running will not change
anything. The service's status can be queried using the svcs(1)
command.