dispadmin(1M) System Administration Commands dispadmin(1M)NAMEdispadmin - process scheduler administration
SYNOPSISdispadmin-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 ver‐
ify 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 dis‐
played 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:/sys‐
tem/scheduler:default. If class name is not specified,
the name and description of the current default sched‐
uling 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/dispad‐
min.conf. Only super-users can set the default schedul‐
ing 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 over‐
writing 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 res‐
olution, 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 con‐
trol 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 lev‐
els) as the table being overwritten. Super-user privi‐
leges 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 ker‐
nel's hz variable. If kernel variable hires_tick is set
to 1 to get higher resolution 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 over‐
writing 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 ALSOpriocntl(1), svcs(1), svcadm(1M), priocntl(2), fx_dptbl(4),
rt_dptbl(4), ts_dptbl(4), attributes(5), smf(5), FSS(7)
System Administration Guide: Basic Administration Programming Inter‐
faces Guide
DIAGNOSTICSdispadmin prints an appropriate diagnostic message if it fails to over‐
write the current scheduler parameters due to lack of required permis‐
sions or a problem with the specified input file.
NOTES
The default scheduling class setting facility is managed by the service
management facility,smf(5), 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(1M). Note that dis‐
abling the service while it is running will not change anything. The
service's status can be queried using the svcs(1) command.
SunOS 5.10 18 Nov 2005 dispadmin(1M)
