Comment 15 for bug 1477171

Agreed that this is an issue with acpi-cpufreq.

turbostat is broken on Trusty:
$ sudo turbostat
/dev/cpu/0/msr offset 0x641 read failed

But using Brendan Gregg's msr-cloud-tools [1] it seems we are actually running at max frequency (with intel_idle.max_cstate=0 processor.max_cstate=0 but without intel_pstate):

$ sudo ./showboost
CPU MHz : 2901
Turbo MHz : 3200 (10 active)
Turbo Ratio : 110% (10 active)
CPU 0 summary every 5 seconds...

TIME C0_MCYC C0_ACYC UTIL RATIO MHz
09:04:00 6554116 7236499 0% 110% 3203
09:04:05 4712681 5202133 0% 110% 3202
09:04:10 4209132 4646582 0% 110% 3202
09:04:15 4560950 5038256 0% 110% 3204

While cpupower still shows us running at 2901:
$ sudo cpupower frequency-info
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us.
  hardware limits: 1.20 GHz - 2.90 GHz
  available frequency steps: 2.90 GHz, 2.90 GHz, 2.80 GHz, 2.70 GHz, 2.50 GHz, 2.40 GHz, 2.30 GHz, 2.20 GHz, 2.00 GHz, 1.90 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance
  current policy: frequency should be within 1.20 GHz and 2.90 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 2.90 GHz (asserted by call to hardware).
  cpufreq stats: 2.90 GHz:100.00%, 2.90 GHz:0.00%, 2.80 GHz:0.00%, 2.70 GHz:0.00%, 2.50 GHz:0.00%, 2.40 GHz:0.00%, 2.30 GHz:0.00%, 2.20 GHz:0.00%, 2.00 GHz:0.00%, 1.90 GHz:0.00%, 1.80 GHz:0.00%, 1.70 GHz:0.00%, 1.60 GHz:0.00%, 1.40 GHz:0.00%, 1.30 GHz:0.00%, 1.20 GHz:0.00%
  boost state support:
    Supported: yes
    Active: yes

[1] https://github.com/brendangregg/msr-cloud-tools