MONITOR TASKS command

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Summary

Privileges
System administrator
Function
Usage statistics for maintask, MP subtasks, and zIIP subtasks

Syntax

MONITOR TASKS

Example 1

MONITOR TASKS

Usage notes

At installations using the MP (multiprocessing) or zIIP feature, the system administrator can use the MONITOR TASKS command to view usage information for all attached Online tasks, including the maintask.

The MONITOR TASKS command displays the data shown in the table below. When the terminal is MODEL=2, as specified by the MODEL parameter, the ZDEQ, SDEQ, LKWTIME, LKPTIME, and ZIPCPU columns are not displayed.

MONITOR TASKS display information

Statistic

Meaning

TASK

The task number. 0 always denotes the maintask, 1 the highest priority offload subtask, 2 the next highest priority subtask, and so forth.

CPU

The total amount of CPU time used by the task (in milliseconds). For a zIIP subtask, this figure includes the CPU actually consumed on the zIIP engine (see ZIPCPU below), plus the overhead of running the zIIP subtask.

PR

Total elapsed time during which the task has been available for offload processing.

PCPU

CPU used, as a percentage of elapsed time (CPU/PR).

WAIT

The number of times the task has issued a real operating system WAIT, excluding waits for MP locks.

POST

The number of times the task issued a real operating system POST, excluding posts for MP locks.

LKWAIT

The number of times the task issued a real operating system WAIT to wait for an MP lock to become available.

LKPOST

The number of times the task issued a real operating system POST to indicate the availability of an MP lock to another task.

MQWTM

The average length of time (in microseconds) required for a unit of work to get to the task from another task. This is a measure of queue delay between maintask and subtasks.

DEQ

The number of units of work taken by the corresponding task - maintask, MP subtask, or zIIP subtask - regardless of the queue that the work was taken from.

ZDEQ

The number of units of work taken from a zIIP queue by either the maintask or an MP subtask. This column has meaning only for the maintask and MP subtasks. For zIIP subtasks this column always contains a zero. Displayed only when the terminal is MODEL=5.

SDEQ

The number of units of work taken from an MP subtask queue by the maintask. This column has meaning only for the maintask; for other tasks this column always contains a zero. Displayed only when the terminal is MODEL=5.

LKWTIME

Lock wait time-Total elapsed time in milliseconds, this task spent waiting for MP locks. Displayed only when the terminal is MODEL=5.

LKPTIME

Lock preemption time-Total elapsed time in milliseconds, this task spent waiting, due to operating system preemption.

This is the elapsed time between when an MP lock becomes available (lock post) making the task ready to run, and when the task actually gets the CPU. That preemption delay is caused by the operating system dispatching other tasks ahead of this task. Displayed only when the terminal is MODEL=5.

ZIPCPU

The total CPU time (in milliseconds) consumed by this zip engine. It is zero for MP subtasks and greater than zero when "z" precedes the task number and that zIIP subtask has been active (AMPSUBZ>0) at some point during the run. Displayed only when the terminal is MODEL=5.

MONITOR TASKS indicates a zIIP subtask by displaying a lowercase letter z beside the subtask number.

Most of the statistics described in the table above are also written to the journal (CCAJRNL) whenever system final or partial statistics are logged. For more information about statistics in journal entries and for general information about task off-loading and related MP concepts, refer to Tracking system activity (CCAJRNL, CCAAUDIT, CCAJLOG) and Multiprocessing (MP/204).

Example 2

When the terminal is MODEL=2, as specified by the MODEL parameter, MONITOR TASKS displays the following columns. The LKWTIME and LKPTIME columns are not displayed.

TASK CPU PR PCPU WAIT POST LKWAIT LKPOST MQWTM DEQ 0 234 834 280 76 14 0 0 179 78 1 0 6 0 10 8 0 0 8000 1 2 0 10 0 1 1 0 0 0 0 z 3 0 16 0 2 1 0 0 0 0 z 4 0 19 0 1 1 0 0 0 0

zIIP processing information

MONITOR TASKS displays three zIIP-related columns, ZDEQ, SDEQ, and ZIPCPU, on screens formatted as a 3270 Model 5 terminal.

See the preceding table for details on these statistics.

Example 3

The following display illustrates the output of a MONITOR TASKS command with zIIP processing statistics, as displayed on the terminal where MODEL=5. The LKWTIME and LKPTIME columns are also displayed.

TASK CPU PR PCPU WAIT POST LKWAIT LKPOST MQWTM DEQ ZDEQ SDEQ LKWTIME LKPTIME ZIPCPU 0 225 824 273 70 14 0 0 189 74 19 10 0 0 0 1 0 6 0 10 8 0 0 8000 1 0 0 0 0 0 2 0 10 0 1 1 0 0 0 0 0 0 0 0 0 z 3 0 16 0 2 1 0 0 0 0 0 0 0 0 0 z 4 0 19 0 1 1 0 0 0 0 0 0 0 0 0