Notable upstream bugs with related issues alegidly patched: https://bugzilla.kernel.org/show_bug.cgi?id=115771 maybe not patched yet: https://bugzilla.kernel.org/show_bug.cgi?id=93521
Workaround (to help other who find this bug) Add `intel_pstate=disable` to `GRUB_CMDLINE_LINUX_DEFAULT` in /etc/default/grub and update-grub. This will revert to the acpi-cpufreq driver and ondemand (default) policy. check with `cpupower frequency-info` I've observed more sane scaling of CPU frequencies, and better fan speed and temperature on Haswell. E.g. acpi-cpufreq vs pstate (while relatively idle) * temp: ~52 vs 70 degrees * fan: ~3800 rpm vs 4600 rpm pstate will very often turbo boost many cores and seldom drop below standard max frequency even when lightly loaded per core. When loaded, temp would bounce up to 89 degrees quickly. I suspect the CPU kept needing to throttle back often. ** Bug watch added: Linux Kernel Bug Tracker #115771 http://bugzilla.kernel.org/show_bug.cgi?id=115771 ** Bug watch added: Linux Kernel Bug Tracker #93521 http://bugzilla.kernel.org/show_bug.cgi?id=93521 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1598394 Title: intel_pstate has too aggressive frequency selection Status in linux package in Ubuntu: Confirmed Bug description: I was recently upgrading from Ubuntu Gnome 15.10 to 16.04 on my ThinkPad. Before the frequency-scaling chose the minimum possible frequency when the system was on low load. Now, when I allow the CPU to choose anything between the lowest and highest possible frequency, it sticks to the highest frequency for 90% of time and only occasionally drops to the low frequency. I can confirm (htop) that my system load is practically zero. Also the CPU Power Manager Applet from Gnome Shell works well, because I can force low frequency by reducing the maximum allowed frequency and can also switch off Turbo Boost. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-generic 4.4.0.28.30 ProcVersionSignature: Ubuntu 4.4.0-28.47-generic 4.4.13 Uname: Linux 4.4.0-28-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: timeshifter 1768 F.... pulseaudio /dev/snd/controlC1: timeshifter 1768 F.... pulseaudio CurrentDesktop: GNOME Date: Sat Jul 2 12:11:42 2016 EcryptfsInUse: Yes HibernationDevice: RESUME=UUID=87cca434-274f-4464-9598-97fd7a1338fe InstallationDate: Installed on 2016-03-19 (104 days ago) InstallationMedia: Ubuntu-GNOME 15.10 "Wily Werewolf" - Release amd64 (20151021) MachineType: LENOVO 20C0003SFR ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/usr/bin/zsh ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-28-generic root=UUID=e52c99ea-9646-4e8a-b8ad-c47b175ac5a3 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-4.4.0-28-generic N/A linux-backports-modules-4.4.0-28-generic N/A linux-firmware 1.157.1 SourcePackage: linux UpgradeStatus: Upgraded to xenial on 2016-07-02 (0 days ago) dmi.bios.date: 11/07/2014 dmi.bios.vendor: LENOVO dmi.bios.version: B0ET24WW (1.11 ) dmi.board.asset.tag: Not Available dmi.board.name: 20C0003SFR dmi.board.vendor: LENOVO dmi.board.version: SDK0E50510 WIN dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvrB0ET24WW(1.11):bd11/07/2014:svnLENOVO:pn20C0003SFR:pvrThinkPadS1Yoga:rvnLENOVO:rn20C0003SFR:rvrSDK0E50510WIN:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.name: 20C0003SFR dmi.product.version: ThinkPad S1 Yoga dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1598394/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
