Siemens U3585-J-Z125-8-76 1 manual Time equivalent for the housekeeping performance

Glossary

The task queues described in the following contain tasks waiting for an event that is very remote in time before they become ready. These tasks are deactivated, i.e. they have lost the right to use main memory.

Q7 Not used

Q8 Not used

Q9 Not used

Q10 Hold queue for tasks placed in the hold state by the system or the operator in an emergency or overload situation. Tasks in the device queue or the WHEN queue. Tasks which cannot be terminated under normal conditions but have not yet been completed (error).

Newly generated tasks.

Q11 System tasks which are not called on a time basis.

Q12 Tasks waiting for an event remote in time, e.g. time-consuming inter-task commu- nication events (boursing, especially waiting for terminal input in interactive mode).

Q13 Tasks waiting for VPASS or PASS end.

The task queues are implemented by chaining the TCBs (task control blocks). In the system, a separate entry refers to the first TCB of each queue.

Task queues Q0 to Q4 exist once for each central processor. Queues Q5 to Q13 are system-global.

time equivalent for the housekeeping performance

The housekeeping performance of the system is a measure of the operating system overhead caused by the workload to be processed. Its definition encompasses the following factors:

1.CPU service time (SIH time) for processing paging requests.

2.Further SIH times for the operating system.

This is for simplification only, because various operations performed in the SIH state constitute productive work. Part of the productive performance for I/O execution occurs in the SIH state. System activities for processing SVC calls (SVC frame processing) are also handled in the SIH state. As far as monitoring is concerned, it would be very complicated to assign the SIH part of the productive performance to the individual tasks.

3.Hardware duration of the I/O operation for paging page transfers.

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