Network Hardware User Manual

U3585-J-Z125-8-76 457
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.
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.
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.