6. DATA SOURCES › 6.4 CPU Time Measurements › 6.4.4 Variability in CPU Time › 6.4.4.5 Paging Rate Effects

6.4.4.5 Paging Rate Effects

Increased paging rates increase captured and non-captured CPU
times alike.

A rising number of page faults implies a rising quantity of
dispatcher time.  Further increases of non-captured time will
occur due to additional RSM and ASM page movement and RCT
processing of swap-ins and swap-outs (RCT CPU time is
captured for the individual address space, but it still
varies proportionately with the number of swaps that occur).
SRB times will increase because of page steal activity and
swap coordination.  Expect additional time for IOS processing
of page and swap I/O, although ASM does have an "express"
path through the IOS code.  Finally, both TCBs and SRBs will
be charged for page reclaims.

When a FREEMAIN or a page steal by SRM results in making a
real page available to an MP system, the page must be
invalidated and both CPUs translation lookaside buffers must
be purged of the entry.  The invalidation and purge are
synchronous:  one CPU may wait (spin) a variable amount of
time until the other CPU is enabled to receive a signal (EMS
interrupt) and perform the synchronizing function.