prctl(1) User Commands prctl(1)NAMEprctl - get or set the resource controls of running processes, tasks,
and projects
SYNOPSISprctl [-P] [-t [basic | privileged | system]]
[-n name [-srx] [-v value]
[-e | -d action] [-p pid]] [-i idtype] id...
DESCRIPTION
The prctl utility allows the examination and modification of the
resource controls associated with an active process, task, or project
on the system. It allows access to the basic and privileged limits on
the specified entity.
See resource_controls(5) for a description of the resource controls
supported in the current release of the Solaris operating system.
OPTIONS
If none of the -s, -r, -x, -v, -d, or -e options are specified, the
invocation is considered a get operation. Otherwise, it is considered a
modify operation.
The following options are supported:
-d | -e action
Disables (-d) or enables (-e) the specified action on the resource
control value specified by -v, -t, and -p. If any of the -v, -t, or
-p options are unspecified, they match any value, privilege, or
recipient pid. For example, specifying only -v modifies the first
resource control with matching value, matching any privilege and
recipient pid. If no matching resource control value is found, a
new value is added as if -s were specified.
Actions:
all This action is only available with -d. It dis‐
ables all actions. This fails on resource con‐
trol values that have the deny global flag.
deny Indicates that the resource control attempts to
deny granting the resource to the process,
task, project, or zone on a request for
resources in excess of the resource control
value. deny actions can not be enabled if the
resource control has the no-deny global flag.
deny actions can not be disabled if the
resource control has the deny global flag.
signal This action is only available with -d. It deac‐
tivates the signal action.
signal=signum In the signal=signum action, signum is a signal
number (or string representation of a signal).
Setting a signal action on a resource control
with the no-local-action global flag fails. A
limited set of signals can be sent. See NOTES
for additional details.
-i idtype
Specifies the type of the id operands. Valid idtypes are process,
task, project, or zone. Also allowed are pid, taskid, projid, and
zoneid. The default id type, if the -i option is omitted, is
process.
For a modify operation, the entity to which id operands are members
is the target entity. For instance, setting a project resource con‐
trol on an -i process sets the resource control on the project to
which each given process argument is a member.
For a get operation, the resource controls are listed for all enti‐
ties to which the id operands are members. For example, -i task
taskid lists the task, project, and zone resource controls for the
task, and for the project and zone to which that task is a member.
-n name
Specifies the name of the resource control to get or set. If the
name is unspecified, all resource controls are retrieved.
-p pid
When manipulating (using -s, -r, -x, -d, or -e) a basic task
project, or zone resource control values, a recipient pid can be
specified using -p. When setting a new basic resource control or
controls on a task, project, or zone, the -p option is required if
the -i idtype option argument is not process.
-P
Display resource control values in semi-colon delimited format.
-r
Replaces the first resource control value (matching with the -t
privilege) with the new value specified through the -v option.
-s
Set a new resource control value.
This option requires the -v option.
If you do not specify the -t option, basic privilege is used. If
you want to set a basic task, process, or zone rctl, -p is
required. If -e or -d are also specified, the action on the new
rctl is set as well.
For compatibility with prior releases, this option is implied if -v
is specified, without any of -e, -d, -r, or -x.
See resource_controls(5) for a description of unit modifiers and
scaling factors you can use to express large values when setting a
resource control value.
-t [ basic | privileged | system ]
Specifies which resource control type to set. Unless the "lower‐
able" flag is set for a resource control, only invocations by users
(or setuid programs) who have privileges equivalent to those of
root can modify privileged resource controls. See rctl‐
blk_set_value(3C) for a description of the RCTL_GLOBAL_LOWERABLE
flag. If the type is not specified, basic is assumed. For a get
operation, the values of all resource control types, including sys‐
tem, are displayed if no type is specified.
-v value
Specifies the value for the resource control for a set operation.
If no value is specified, then the modification (deletion, action
enabling or disabling) is carried out on the lowest-valued resource
control with the given type.
See resource_controls(5) for a description of unit modifiers and
scaling factors you can use to express large values when setting a
resource control value.
-x
Deletes the specified resource control value. If the delete option
is not provided, the default operation of prctl is to modify a
resource control value of matching value and privilege, or insert a
new value with the given privilege. The matching criteria are dis‐
cussed more fully in setrctl(2).
If none of the -d, -e, -v, or -x options is specified, the invocation
is considered a get operation.
OPERANDS
The following operand is supported:
id The ID of the entity (process, task, project, or zone) to
interrogate. If the invoking user's credentials are
unprivileged and the entity being interrogated possesses
different credentials, the operation fails. If no id is
specified, an error message is returned.
EXAMPLES
Example 1 Displaying Current Resource Control Settings
The following example displays current resource control settings for a
task to which the current shell belongs:
example$ ps -o taskid -p $$
TASKID
8
example$ prctl-i task 8
136150: /bin/ksh
NAME PRIVILEGE VALUE FLAG ACTION RECIPIENT
task.max-cpu-time
system 18.4Es inf none -
task.max-lwps
system 2.15G max deny -
project.max-contracts
privileged 10.0K - deny -
project.max-locked-memory
privileged 127MB - deny -
project.max-port-ids
privileged 8.19K - deny -
project.max-shm-memory
privileged 508MB - deny -
project.max-shm-ids
privileged 128 - deny -
project.max-msg-ids
privileged 128 - deny -
project.max-sem-ids
privileged 128 - deny -
project.max-crypto-memory
privileged 508MB - deny -
project.max-tasks
system 2.15G max deny -
project.max-lwps
system 2.15G max deny -
project.cpu-shares
privileged 1 - none -
zone.max-lwps
system 2.15G max deny -
zone.cpu-shares
privileged 1 - none -
Example 2 Displaying, Replacing, and Verifying the Value of a Specific
Control
The following examples displays, replaces, and verifies the value of a
specific control on an existing project:
example# prctl-n project.cpu-shares -i project group.staff
project: 10: group.staff
NAME PRIVILEGE VALUE FLAG ACTION RECIPIENT
project.cpu-shares
privileged 1 - none -
system 65.5K max none -
example# prctl-n project.cpu-shares -v 10 -r -i project group.staff
example# prctl-n project.cpu-shares -i project group.staff
project: 10: group.staff
NAME PRIVILEGE VALUE FLAG ACTION RECIPIENT
project.cpu-shares
privileged 10 - none -
system 65.5K max none -
Example 3 Adjusting Resources
The following example uses the project.max-locked-memory resource.
First, use id -p to find out which project the current shell is a mem‐
ber of:
/home/garfield> id -p
uid=77880(garfield) gid=10(staff) projid=10(group.staff)
Using the target project, identify the resource limit value before the
change:
/home/garfield> prctl-n project.max-locked-memory -i project \
group.staff
project 10: group.staff
project.max-locked-memory
privileged 256MB - deny -
system 16.0EB max deny -
current limit is 256 Megabytes.
Next, adjust the project.max-locked-memory limit to 300 Megabytes for
the target project:
# prctl-n project.max-locked-memory -v 300M -r -i project group.staff
The resource limit value after the change shows a new value of 300
Megabytes:
# prctl-n project.max-locked-memory -i project group.staff
project 10:group.staff
project.max-locked-memory
privileged 300MB - deny -
system 16.0EB max deny -
Example 4 Modifying CPU Caps for a Project
The prctl command can use the project.cpu-cap resource control (see
resource_controls(5)) to set and modify CPU caps for a project. (The
same resource control can be used in the /etc/project file. See
project(4)) The following command modifies the CPU cap to limit
user.smith to three CPUs:
# prctl-r -t privileged -n project.cpu-cap -v 300 -i project user.smith
The prctl-r option, used above, is used to dynamically change a CPU
cap for a project or zone. For example, the following command will
change the cap set in the preceding command to 80 percent:
# prctl-r -t privileged -n project.cpu-cap -v 80 -i project user.smith
To remove a CPU cap, enter:
# prctl-x -n project.cpu-cap $$
Example 5 Modifying CPU Caps for a Zone
The prctl command can use the zone.cpu-cap resource control (see
resource_controls(5)) to set and modify CPU caps for a zone. (The same
resource control can be manipulated using the zonecfg(1M) command.) The
following command modifies the CPU cap to limit the global zone to 80
percent of a CPU:
# prctl-t privileged -n zone.cpu-cap -v 80 -i zone global
The cap can be lowered to 50% using:
# prctl-r -t privileged -n zone.cpu-cap -v 50 -i zone global
EXIT STATUS
The following exit values are returned:
0 Successful completion.
1 Fatal error encountered.
2 Invalid command line options were specified.
FILES
/proc/pid/* Process information and control files
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │SUNWesu │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │See below. │
└─────────────────────────────┴─────────────────────────────┘
The command-line syntax is Evolving. The human-readable output is
Unstable. The parseable output is Evolving.
SEE ALSOrctladm(1M), zonecfg(1M), setrctl(2), rctlblk_get_local_action(3C),
project(4), attributes(5), resource_controls(5)NOTES
The valid signals that can be set on a resource control block allowing
local actions are SIGABRT, SIGXRES, SIGHUP, SIGSTOP, SIGTERM, and
SIGKILL. Additionally, CPU time related controls can issue the SIGXCPU
signal, and file size related controls can send the SIGXFSZ signal.
SunOS 5.10 7 Mar 2007 prctl(1)
