Testing with a graduated workload shows how well event mode works.
cpupm is set to event-mode,
c-state is disabled,
the hardware platfrom has 8 cores.
monitor dtrace probe "ess_transition"
The result is as follows:
=========================================
average | the numbers of the probe
system workload | is hitted per minutes(60s)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
0% | 243
13% | 28195
26% | 5379
38% | 8723
51% | 9939
63% | 12259
76% | 10611
88% | 11907
100% | 13443
========================================
The average system workload was obtained from (100 - vmstat.idle).
>From the result, we can see, event-mode is too sensitive to properly drive
the p-state transition. this could be a reason to impact performance.
Any thoughts?
Thanks,
-Aubrey
