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 specified below.

Category             Res Ctrl      Modifier  Scale


                     Type String
-----------          -----------   --------  -----
Size                 bytes         B         1


                                   KB        2^10


                                   MB        2^20


                                   GB        2^30


                                   TB        2^40


                                   PB        2^50


                                   EB        2^60
Time                 seconds       s         1


                                   Ks        10^3


                                   Ms        10^6


                                   Gs        10^9


                                   Ts        10^12


                                   Ps        10^15


                                   Es        10^18
Count                integer       none      1


                                   K         10^3


                                   M         10^6


                                   G         10^9


                                   T         10^12


                                   P         10^15


                                   Es        10^18

Scaled values can be used with resource controls. The following example shows a scaled threshold value:

task.max-lwps=(priv,1K,deny)

In the project file, the value 1K is expanded to 1000:

task.max-lwps=(priv,1000,deny)

A second example uses a larger scaled value:

process.max-file-size=(priv,5G,deny)

In the project file, the value 5G is expanded to 5368709120:

process.max-file-size=(priv,5368709120,deny)

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(8), and projmod(8) commands. You cannot use unit modifiers 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 occur.

Each threshold value on a resource control must be associated with a privilege level. The privilege level must be one of the following three types:

basic

privileged

system

A resource control is guaranteed to have one system value, which is defined by the system, or resource provider. The system value represents 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_PRIVILEGED, 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:

task.max-lwps=(priv,1K,deny)

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(8) to perform the following 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 control, you can associate one or more actions. There are three types of local actions: none, deny, and signal=. These three actions are used as follows:

none

deny

signal=

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(8).) 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:

SIGABRT

SIGHUP

SIGTERM

SIGKILL

SIGSTOP

SIGXRES

SIGXFSZ

SIGXCPU

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(8) or the setrctl(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 setrctl(2).

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:

lowerable

no-deny

cpu-time

seconds

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


 process.max-cpu-time


         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.