Not sure why this was initially rejected. It sounds reasonable to have it now as there are (and will be HWE kernels with the intel_pstate drive).
SRU justification: Impact: When using HWE kernels in Trusty one can be using the intel_pstate driver which will result in no other power saving governor than powersave available. Given the choices (or lack of them) it is better for power usage to fall back to that instead of keeping the performance governor active. Fix: Apply the same change we have for Utopic and add the powersave governor as the last option to check and activate. Testcase: See reproducer in description. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to sysvinit in Ubuntu. https://bugs.launchpad.net/bugs/1314653 Title: sysvinit: default cpufreq governor to powersave for intel-pstate driver Status in sysvinit package in Ubuntu: Fix Released Status in sysvinit source package in Trusty: Confirmed Status in sysvinit source package in Utopic: Fix Released Bug description: When defaulting to the intel-pstate driver, there are only a couple of cpufreq governors available, none of which are handled in the /etc/init.d/ondemand script. Since this driver is meant to be used for power saving, it seems wrong to leave the system in the kernel default configured "performance" governor after boot, so I think it is pertinent to set this to "powersave" if it is the only suitable non-power hungry governor available. How to reproduce: 1. enable the intel_pstate driver on a recent Intel machine (Sandybridge or above) edit /etc/default/grub, modify the following: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_pstate=enable" and run: sudo update-grub and reboot. 2. login 3. wait at least 60 seconds for /etc/init.d/ondemand to complete check out the default cpufreq governor, you will see it is still set to the boot default of "performance": cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor With the attached fix the system will boot into a less aggressive cpufreq governor. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/sysvinit/+bug/1314653/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
