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|man pages section 3: Library Interfaces and Headers Oracle Solaris 11 Express 11/10|
- pool configuration manipulation library
cc [ flag... ] file... [ library... ] #include <pool.h>
The functions in this library define the interface for reading and writing resource pools configuration files, as well as that for commiting an existing configuration to becoming the running OS configuration (with respect to partitioning subsystems). The <pool.h> header provides type and function declarations for all library services.
The resource pools facility brings together process-bindable resources into a common abstraction called a pool. Processor sets and other entities can be configured, grouped, and labelled in a persistent fashion such that workload components can be associated with a subset of a system's total resources. The libpool library provides a C language API for accessing this functionality, while pooladm(1M), poolbind(1M), and poolcfg(1M) make this facility available through command invocations from a shell. Each of those manual pages describes aspects of the pools facility; this page describes the properties available to the various entities managed within the pools facility. These entities include the system, pools, and the pset resources for processor sets.
When the pools facility is enabled on a system, the behavior of the following functions is modified.
Each active entity within the resource pools framework can have an arbitrary collection of named, typed properties associated with it. Properties supported by the pools framework are listed, with descriptions, under each entity below. In general, resource properties can be one of five types: boolean (bool), signed (int64) and unsigned (uint64) integers, floating point (double), and string values.
All entities and resources support a string property for commenting purposes; this property is available for use by management applications to record descriptions and other administrator oriented data. The comment field is not used by the default pools commands, except when a configuration is initiated by the poolcfg utility, in which case an informative message is placed in the system.comment property for that configuration.
The system.allocate-method, system.bind-default, system.comment, system.name, system.poold.log-level, system.poold.log-location, system.poold.history-file, system.poold.monitor-interval, and system.poold.objectives properties are writable; the system.version property is not.
The system.allocate-method property accepts only two values, “importance based” and “surplus to default”. The default value for this property is “importance based”. The property is optional and if it is not present the library will allocate resources as though it were present and had the default value. These strings are defined in <pool.h> as POA_IMPORTANCE and POA_SURPLUS_TO_DEFAULT.
If “importance based” allocation is defined, then during a commit the library will allocate resources to pools using an algorithm that observes minimum and maximum constraints for resources but favors those resources with greater importance.
If “surplus to default” is defined, then during a commit the library will allocate minimum resources to all resource sets apart from default which will receive any surplus.
The system.bind-default property defaults to true. This property interacts with the project.pool resource control to specify the binding behavior for processes associated with a project. If project.pool is not specified, then this property has no effect. If project.pool is specified and the specified pool exists, this property has no effect. If the specified pool does not exist, perhaps because of a reconfiguration, then this property controls the binding behavior for the project member. If system.bind-default is true, then the project member is bound to the default pool (identified as the pool for which pool.default is true); otherise the project member is refused access to the system. Care should be taken with the pools configuration if this property is set to false, so as to avoid denying users access to the system.
The various poold properties are used to configure the operation of poold(1M).
The system.poold.log-level property is used to specify the level of detail provided in log messages. Valid values are: ALERT, CRIT, ERR, WARNING, NOTICE, INFO, and DEBUG.
ALERT provides the least level of detail, DEBUG the greatest. See syslog(3C) for more information about the meaning of these debug levels. If this property is not specified, the default value NOTICE is used.
The system.poold.log-location property is used to specify the location of the logfiles generated by poold. The special value of “syslog” indicates that logged messages should be written to syslog(). If this property is not specified, the default location /var/log/pool is used.
The system.poold.history-file specifies the location of the decision history file which is used by poold to improve the quality of its decision making over time. If this property is not specified, the default location /var/adm/pool is used.
The system.poold.monitor-interval property specifies the monitoring interval (in milliseconds) to be used by poold when sampling utilization statistics. If this property is not specified, the default value of 15 seconds is used.
The system.poold.objectives property specifies any system wide objectives. An objectives property has the following syntax:
objectives = objective [; objective]* objective = [n:] keyword [op] [value]
All objectives are prefixed with an optional importance. The importance acts as a multiplier for the objective and thus increases the significance of its contribution to the objective function evaluation. If no importance is specified, the default value is 1.
The “wt-load” objective is the only objective to which a system element can be set. This objective favors configurations that match resource allocations to resource utilization. A resource set that uses more resources will be given more resources when this objective is active. An administrator should use this objective when he is relatively satisfied with the constraints established using the minimum and maximum properties and would like the DRP to manipulate resources freely within those constraints.
The pool.default, pool.sys_id, and pool.temporary properties are not writable; all other listed properties are writable.
If pool.scheduler is specified, it must be set to the name of a valid scheduling class for the system. See the -c option for priocntl(1) for a list of valid class names.
The pset.comment, pset.max, pset.min, pset.name, and pset.poold.objectives properties are writable; the pset.default, pset.load, pset.size, pset.sys_id, pset.temporary, pset.type, and pset.units properties are not.
The pset.load property represents the load on a processor set. The lowest value for this property is 0. The value of pset.load increases in a linear fashion with the load on the set, as measured by the number of jobs in the system run queue.
The pset.poold.objectives property specifies an objective which is specific to a particular pset. See the system.poold.objectives entry for the specification of this property's syntax.
There are two types of objectives that can be set on a pset:
This objective influences the impact that locality, as measured by lgroup data, has upon the chosen configuration. This objective can take one of three values:
If set, configurations that maximize resource locality are favored.
If set, configurations that minimize resource locality are favored.
This is the default value for this objective. If set, configuration favorability is uninfluenced by resource locality.
This objective favors configurations that allocate resources to partitions that are failing to preserve the specified utilization objective.
These objectives are specified in terms of an operator and a value. The operators are
The ``less than'' operator is used to indicate that the specified value should be treated as a maximum target value.
The ``greater than'' operator is used to indicate that the specified value should be treated as a minimum target value.
The ``about'' operator is used to indicate that the specified value should be treated as a target value about which some fluctuation is acceptable.
Only one objective of each type of operator can be set. For example, if the ~ operator is set, the < and > operators cannot be set. It is possible to set a < and a > operator together; the values will be validated to ensure that they do not overlap.
The cpu.comment, cpu.pinned, and cpu.status properties are writeable.
The cpu.status property can be set only to the following values:
Set the CPU offline.
Set the CPU online.
Disable interrupt processing on the CPU.
These values are defined in <sys/processor.h> as the PS_OFFLINE, PS_ONLINE, and PS_NOINTR macros.
The shared object libpool.so.1 provides the public interfaces defined below. See Intro(3) for additional information on shared object interfaces.
64-bit shared object
See attributes(5) for descriptions of the following attributes:
Intro(3), pool_component_info(3POOL), pool_conf_open(3POOL), pool_conf_to_elem(3POOL), pool_create(3POOL), pool_error(3POOL), pool_get_binding(3POOL), pool_get_property(3POOL), pool_get_resource(3POOL), pool_resource_create(3POOL), pool_value_alloc(3POOL), pool_walk_pools(3POOL), attributes(5), smf(5)
Functions in libpool can be used to manipulate static configurations even when the pools facility is not enabled. See pooladm(1M) and pool_set_status(3POOL) for more information about enabling the pools facility. The pools facility must be enabled, however, to modify the dynamic configuration.
Since the Resource Pools facility is an smf(5) service, it can also be enabled and disabled using the standard Service Management Facility (SMF) interfaces.