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 speci-
fied 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 output-
ting 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 prior-
ity 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 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
overwriting it.
EXAMPLES
Example 1: Retrieving the Current Scheduler Parameters for
the real-time class
The following command retrieves the current scheduler param-
eters 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 param-
eters 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 speci-
fied in ts.config.
dispadmin -c TS -s ts.config
FILES
/etc/dispadmin.conf
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| 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 Program-
ming Interfaces Guide
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.
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