Comment 5 for bug 1640000

I have it both on a MacBook Air 2011 11" and a MacBook Pro 2015 13"

This is a bug in 16.10
It did not exist in 16.04
It appears to be for ALL 16.10 kernels to date, ie. from 8/27/2016 onwards

MacBook Pro:
uname --kernel-release --kernel-version
4.8.0-27-generic #29-Ubuntu SMP Thu Oct 20 21:03:13 UTC 2016

MacBook Air:
uname --kernel-release --kernel-version
4.8.0-27-generic #29-Ubuntu SMP Thu Oct 20 21:03:13 UTC 2016

It is triggered by not high temperture but some flawed conclusions
Once kidle_inject launch they eat 50% of available cpu power forever

Perhaps it is triggered by watching flash video from cnn in Chromium

syslog when triggered:
grep powerclamp /var/log/syslog
Nov 17 10:04:22 c89 kernel: [82843.821614] intel_powerclamp: Start idle injection to reduce power

reading temperatures on MacBook Pro:
sensors | egrep "^(Right|Core|TCGC|TB0T)"
Core 0: +69.0°C (high = +105.0°C, crit = +105.0°C)
Core 1: +68.0°C (high = +105.0°C, crit = +105.0°C)
Right Side : 3097 RPM (min = 1299 RPM, max = 6199 RPM)
TB0T: +36.8°C
TCGC: +71.0°C
- the TCGC is GPU which is what supposedly should trigger about 85 °C

Fix to next reboot: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1389077/comments/6
rmmod intel_powerclamp

Across reboot fix: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1389077/comments/12

Just another bug in i915. Don’t expect a fix anytime soon, so just disable if it happens to your computer