resource_controls - resource controls available through project database
The resource controls facility is configured through the project database. See project(4). You can set and modify resource controls through
the following utilities:
In a program, you use setrctl(2) to set resource control values.
In addition to the preceding resource controls, there are resource pools, accessible through the pooladm(1M) and poolcfg(1M) utilities. In
a program, resource pools can be manipulated through the libpool(3LIB) library.
The following are the resource controls available in the current release of the Solaris operating system.
Number of CPU shares granted to a project for use with the fair share scheduler (see FSS(7)). The unit used is the number of shares
Total amount of locked memory allowed, expressed as a number of bytes.
Maximum allowable number of event ports, expressed as an integer.
Maximum number of shared memory IDs allowed for a project, expressed as an integer.
Maximum number of semaphore IDs allowed for a project, expressed as an integer.
Maximum number of message queue IDs allowed for a project, expressed as an integer.
Total amount of shared memory allowed for a project, expressed as a number of bytes.
Maximum number of LWPs simultaneously available to a project, expressed as an integer.
Maximum number of tasks allowable in a project, expressed as an integer.
Maximum number of contracts allowed in a project, expressed as an integer.
Maximum amount of kernel memory that can be used for crypto operations. Allocations in the kernel for buffers and session-related
structures are charged against this resource control.
Binds a specified resource pool with a project.
Maximum CPU time that is available to this task's processes, expressed as a number of seconds.
Maximum number of LWPs simultaneously available to this task's processes, expressed as an integer.
Maximum CPU time that is available to this process, expressed as a number of seconds.
Maximum file descriptor index available to this process, expressed as an integer.
Maximum file offset available for writing by this process, expressed as a number of bytes.
Maximum size of a core file created by this process, expressed as a number of bytes.
Maximum heap memory available to this process, expressed as a number of bytes.
Maximum stack memory segment available to this process, expressed as a number of bytes.
Maximum amount of address space, as summed over segment sizes, that is available to this process, expressed as a number of bytes.
Maximum allowable number of events per event port, expressed as an integer.
Maximum number of semaphores allowed per semaphore set, expressed as an integer.
Maximum number of semaphore operations allowed per semop call (value copied from the resource control at semget() time). Expressed as
an integer, specifying the number of operations.
Maximum number of bytes of messages on a message queue (value copied from the resource control at msgget() time), expressed as a number
Maximum number of messages on a message queue (value copied from the resource control at msgget() time), expressed as an integer.
The total amount of physical memory, in bytes, that is available to processes in a project.
In the current release, there are the following zone-wide resource controls:
Sets a limit on the number of fair share scheduler (FSS) CPU shares for a zone. CPU shares are first allocated to the zone, and then
further subdivided among projects within the zone as specified in the project.cpu-shares entries. Expressed as an integer.
Enhances resource isolation by preventing too many LWPs in one zone from affecting other zones. A zone's total LWPs can be further sub-
divided among projects within the zone within the zone by using project.max-lwps entries. Expressed as an integer.
Units Used in Resource Controls
Resource controls can be expressed as in units of size (bytes), time (seconds), or as a count (integer). These units use the strings speci-
Category Res Ctrl Modifier Scale
----------- ----------- -------- -----
Size bytes B 1
Time seconds s 1
Count integer none 1
Scaled values can be used with resource controls. The following example shows a scaled threshold value:
In the project file, the value 1K is expanded to 1000:
A second example uses a larger scaled value:
In the project file, the value 5G is expanded to 5368709120:
The preceding examples use the scaling factors specified in the table above.
Note that unit modifiers (for example, 5G) are accepted by the prctl(1), projadd(1M), and projmod(1M) commands. You cannot use unit modi-
fiers in the project database itself.
Resource Control Values and Privilege Levels
A threshold value on a resource control constitutes a point at which local actions can be triggered or global actions, such as logging, can
Each threshold value on a resource control must be associated with a privilege level. The privilege level must be one of the following
Can be modified by the owner of the calling process.
Can be modified only by privileged (superuser) callers.
Fixed for the duration of the operating system instance.
A resource control is guaranteed to have one system value, which is defined by the system, or resource provider. The system value repre-
sents how much of the resource the current implementation of the operating system is capable of providing.
Any number of privileged values can be defined, and only one basic value is allowed. Operations that are performed without specifying a
privilege value are assigned a basic privilege by default.
The privilege level for a resource control value is defined in the privilege field of the resource control block as RCTL_BASIC, RCTL_PRIVI-
LEGED, or RCTL_SYSTEM. See setrctl(2) for more information. You can use the prctl command to modify values that are associated with basic
and privileged levels.
In specifying the privilege level of privileged, you can use the abbreviation priv. For example:
Global and Local Actions on Resource Control Values
There are two categories of actions on resource control values: global and local.
Global actions apply to resource control values for every resource control on the system. You can use rctladm(1M) to perform the following
o Display the global state of active system resource controls.
o Set global logging actions.
You can disable or enable the global logging action on resource controls. You can set the syslog action to a specific degree by assigning a
severity level, syslog=level. The possible settings for level are as follows:
By default, there is no global logging of resource control violations.
Local actions are taken on a process that attempts to exceed the control value. For each threshold value that is placed on a resource con-
trol, you can associate one or more actions. There are three types of local actions: none, deny, and signal=. These three actions are used
No action is taken on resource requests for an amount that is greater than the threshold. This action is useful for monitoring resource
usage without affecting the progress of applications. You can also enable a global message that displays when the resource control is
exceeded, while, at the same time, the process exceeding the threshhold is not affected.
You can deny resource requests for an amount that is greater than the threshold. For example, a task.max-lwps resource control with
action deny causes a fork() system call to fail if the new process would exceed the control value. See the fork(2).
You can enable a global signal message action when the resource control is exceeded. A signal is sent to the process when the threshold
value is exceeded. Additional signals are not sent if the process consumes additional resources. Available signals are listed below.
Not all of the actions can be applied to every resource control. For example, a process cannot exceed the number of CPU shares assigned to
the project of which it is a member. Therefore, a deny action is not allowed on the project.cpu-shares resource control.
Due to implementation restrictions, the global properties of each control can restrict the range of available actions that can be set on
the threshold value. (See rctladm(1M).) A list of available signal actions is presented in the following list. For additional information
about signals, see signal(3HEAD).
The following are the signals available to resource control values:
Terminate the process.
Send a hangup signal. Occurs when carrier drops on an open line. Signal sent to the process group that controls the terminal.
Terminate the process. Termination signal sent by software.
Terminate the process and kill the program.
Stop the process. Job control signal.
Resource control limit exceeded. Generated by resource control facility.
Terminate the process. File size limit exceeded. Available only to resource controls with the RCTL_GLOBAL_FILE_SIZE property
(process.max-file-size). See rctlblk_set_value(3C).
Terminate the process. CPU time limit exceeded. Available only to resource controls with the RCTL_GLOBAL_CPUTIME property (process.max-
cpu-time). See rctlblk_set_value(3C).
Resource Control Flags and Properties
Each resource control on the system has a certain set of associated properties. This set of properties is defined as a set of flags, which
are associated with all controlled instances of that resource. Global flags cannot be modified, but the flags can be retrieved by using
either rctladm(1M) or the getrctl(2) system call.
Local flags define the default behavior and configuration for a specific threshold value of that resource control on a specific process or
process collective. The local flags for one threshold value do not affect the behavior of other defined threshold values for the same
resource control. However, the global flags affect the behavior for every value associated with a particular control. Local flags can be
modified, within the constraints supplied by their corresponding global flags, by the prctl command or the setrctl system call. See
For the complete list of local flags, global flags, and their definitions, see rctlblk_set_value(3C).
To determine system behavior when a threshold value for a particular resource control is reached, use rctladm to display the global flags
for the resource control . For example, to display the values for process.max-cpu-time, enter:
$ rctladm process.max-cpu-time
process.max-cpu-time syslog=off [ lowerable no-deny cpu-time inf seconds ]
The global flags indicate the following:
Superuser privileges are not required to lower the privileged values for this control.
Even when threshold values are exceeded, access to the resource is never denied.
SIGXCPU is available to be sent when threshold values of this resource are reached.
The time value for the resource control.
Use the prctl command to display local values and actions for the resource control. For example:
$ prctl -n process.max-cpu-time $$
process 353939: -ksh
NAME PRIVILEGE VALUE FLAG ACTION RECIPIENT
privileged 18.4Es inf signal=XCPU -
system 18.4Es inf none
The max (RCTL_LOCAL_MAXIMAL) flag is set for both threshold values, and the inf (RCTL_GLOBAL_INFINITE) flag is defined for this resource
control. An inf value has an infinite quantity. The value is never enforced. Hence, as configured, both threshold quantities represent
infinite values that are never exceeded.
Resource Control Enforcement
More than one resource control can exist on a resource. A resource control can exist at each containment level in the process model. If
resource controls are active on the same resource at different container levels, the smallest container's control is enforced first. Thus,
action is taken on process.max-cpu-time before task.max-cpu-time if both controls are encountered simultaneously.
See attributes(5) for a description of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|Interface Stability |Evolving |
prctl(1), pooladm(1M), poolcfg(1M), projadd(1M), projmod(1M), rctladm(1M), setrctl(2), rctlblk_set_value(3C), libpool(3LIB), project(4),
7 Jan 2005 resource_controls(5)