Comment 20 for bug 1188647

Kernel 3.15 contains some intel_pstate changes that should address the issues I raised in post 16 above.

For Ubuntu one concern is: For the 250 Hz kernel the default sample rate will result in an actual different sample rate, and thus the response curve is a little different than for the 1000 Hz kernel. The desire is to have the default sample rate be 12 milliseconds instead of 10 (3 jiffies for 250 Hertz and 10 jiffies for 1000 Hz). This change is on the to-do list. This is probably a minor issue.

For this change:
"intel_pstate: add sample time scaling" I have a concern (and a ton of evidence to support it) that often, but very dependent on periodic workloads, the deferrable timer is delayed when it is not expected to be delayed, and sometimes by a huge amount (4 seconds). The result can be lower than expected CPU frequencies, because new the scale down code kicks in when it shouldn't.