Section: User Commands (1)
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nulltime - Measure CPU utilization by time available to null process
nulltime [loops [repeats]]
Measures the time for a low priority process to execute a
certain number of operations.
This is used in a pair of runs, one with an unloaded system, and
one with a loaded system.
Utilization = (1 - unloaded/loaded) x 100 %
loops - the number of operations to be executed in a loop. (Default 10000000)
repeats - an additional multiplier of loops, in case the CPU is too fast.
$ time nulltime 1000000 1000&
$ spin 10000
$ 40.607864 secs for 1000 x 1000000 operations
$ time nulltime 1000000 1000
30.539456 secs for 1000 x 1000000 operations
Using the above formula, during the interval measured by nulltime, the
CPU utilization is 25%.
The code is perfect.
David Horton - CiTR
Centre for Information Technology Research, 1993
- Known Bugs
This document was created by
using the manual pages.
Time: 23:34:46 GMT, September 27, 2019