Control allocation of CPU, main memory and I/O processor resources to tasks
Component: | BS2000 |
Functional area: | System control and optimization |
Domain: | SYSTEM-TUNING |
Privileges: | TSOS |
Routing code: | R |
Function
Systems support staff can use the MODIFY-TASK-CATEGORIES command to define the number of tasks per category which are competing for the resources CPU, main memory and I/O processor (active tasks), to decide on the priorities of the categories, and to assign I/O priorities for the tasks of a category.
Together with the CHANGE-TASK-PRIORITY command, this command enables systems support staff to specify the distribution of the resources CPU and main memory to the individual tasks. In addition to the four categories with the standard names TP, DIALOG, BATCH and SYS, the task management also supports 12 further categories whose names are declared with the JMU utility routine.
Systems support can modify the assignment of individual tasks to a category using the MOVE-TASK-TO-CATEGORY command.
Systems support defines in the user catalog and job classes allocated to the user the task attributes the user can add on to his tasks.
The I/O priorities are evaluated solely by the IORM subsystem for task-specific control of inputs/outputs, with runtime control both by PRIOR and by the PCS subsystem.
The current values for resource distribution can be displayed by means of the SHOW-SYSTEM-STATUS command.
Format
MODIFY-TASK-CATEGORIES |
CATEGORY-NAME = <name 1..7> / *DIALOG / *BATCH / *TP ,WEIGHT-CODE = *UNCHANGED / <integer 1..511> ,MINIMUM-ACTIVE-TASKS = *UNCHANGED / <integer 0..4095> ,MAXIMUM-ACTIVE-TASKS = *UNCHANGED / <integer 0..4095> ,IO-PRIORITY = *UNCHANGED / *NONE / *LOW / *MEDIUM / *HIGH |
Operands
CATEGORY-NAME = <name 1..7> / *DIALOG / *BATCH / *TP
Name of the category.
WEIGHT-CODE = *UNCHANGED / <integer 1..511>
This operand serves to weight the categories and controls task activation and task initiation (CPU allocation). It influences the relationships in which tasks are activated from categories. In addition, it is taken into consideration when setting the internal task priority which controls the CPU allocation.
A high value indicates a high degree of urgency.
MINIMUM-ACTIVE-TASKS = *UNCHANGED / <integer 0..4095>
Minimum number of tasks in the specified category which must be active. This ensures a minimum workload per category.
MAXIMUM-ACTIVE-TASKS = *UNCHANGED / <integer 0..4095>
Maximum number of tasks in the specified category which must be active. This operand establishes a workload limit in cases of overload.
IO-PRIORITY = *UNCHANGED / *NONE / *LOW / *MEDIUM / *HIGH
Determines the I/O priority of all tasks of the specified category. This value is evaluated only if the IORM subsystem has been started and priority control is active (IORM statement IOPT_SET_ON=YES). The default *NONE means that all tasks of this category are assigned an I/O priority which is derived from the task priority (implicit I/O priority).
Return codes
(SC2) | SC1 | Maincode | Meaning |
|---|---|---|---|
0 | CMD0001 | No error | |
2 | 0 | EXC049B | The PCS subsystem, is active; details will only be stored for PRIOR |
64 | EXC045D | Invalid parameter | |
64 | EXC046B | Invalid category name | |
64 | EXC046C | No access to the SYS category | |
64 | CMD0216 | Privilege infringement |
Example
/show-sys-sta inf=*category
CATEGORY MIN MAX WT #EXIS #ACT #READY #RDY NOT IO-PRIO NAME MPL MPL TING INACT ADMITTED SYS 0030 0064 512 0101 0028 0000 0000 NONE DIALOG 0001 0999 001 0001 0001 0000 0000 NONE BATCH 0001 0999 001 0006 0000 0000 0000 NONE TP 0001 0999 001 0007 0001 0000 0000 NONE BATCHF 0001 0999 001 0005 0002 0000 0000 NONE
/mod-task category-name=dialog,min-act=10,max-act=100
% EXC046D PROCESSING OF /MODIFY-TASK-CATEGORIES COMPLETED
/show-sys-sta inf=*category
CATEGORY MIN MAX WT #EXIS #ACT #READY #RDY NOT IO-PRIO NAME MPL MPL TING INACT ADMITTED SYS 0030 0064 512 0101 0025 0000 0000 NONE DIALOG 0010 0100 001 0001 0001 0000 0000 NONE BATCH 0001 0999 001 0006 0000 0000 0000 NONE TP 0001 0999 001 0007 0001 0000 0000 NONE BATCHF 0001 0999 001 0005 0002 0000 0000 NONE BATCHF 0001 0999 001 0002 0002 0000 0000 NONE