just for completeness (in case someone looks for a wrokaround), adding intel_pstate=disable to GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub and running sudo update-grub got me the ondemand driver back and got the system back to behave as stable as in 14.10.
-- 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/1460399 Title: ivybridge system gets completely unusable after upgrade to vivid thanks to defaulting to immature intel_pstate driver Status in linux package in Ubuntu: New Bug description: I finally got around to upgrade my work laptop (first gen dell XPS sputnik system (ivy bridge)) yesterday, to find myself with a completely unusable and sluggish desktop, constantly spinning CPU fans and a hot enough laptop case that you can burn your fingers after the first reboot after install ... the device didn't stay on for more than 10-15min in a row before the BIOS temperature monitor initiated emergency shutdowns. i also noticed a constant load average above 30.00 in htop after a few hours of researching i found that we apparently switched to the intel_pstate driver by default in vivid ... running a very simple script like: while true; do clear cat /proc/cpuinfo |grep MHz sleep 1 done ...revealed that the cores unconditionally switch to something like 133MHz even though there is currently a lot going on in the system (firefox trying to recover 150 tabs after boot, evolution syncing with an IMAP server etc). it looks to me like the intel_pstate driver (at least on ivybridge hardware) is far from being ready for end users and if i wouldn't have known how to do a detailed research on these issues i would most likely have switched to another distro or to a different known working ubuntu release. could we turn this default back to the ondemand cpufreq governor in an SRU until the driver has matured enough, so we do not lose our ivybridge users and do not generate bad press ? ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: linux-image-3.19.0-18-generic 3.19.0-18.18 ProcVersionSignature: Ubuntu 3.19.0-18.18-generic 3.19.6 Uname: Linux 3.19.0-18-generic x86_64 ApportVersion: 2.17.2-0ubuntu1.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: ogra 2120 F.... pulseaudio CurrentDesktop: Unity Date: Sun May 31 11:53:35 2015 DistributionChannelDescriptor: # This is a distribution channel descriptor # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor canonical-oem-somerville-precise-amd64-20120703-2 HibernationDevice: RESUME=UUID=145593f3-8085-4308-99b1-e1ff9c80f273 InstallationDate: Installed on 2013-11-05 (572 days ago) InstallationMedia: Ubuntu 12.04 "Precise" - Build amd64 LIVE Binary 20120703-15:08 MachineType: Dell Inc. XPS L322X ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-18-generic root=UUID=d0a6e4d2-9705-4ce3-97be-8ec33e06f2cb ro quiet splash intel_pstate=disable crashkernel=384M-:128M vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.19.0-18-generic N/A linux-backports-modules-3.19.0-18-generic N/A linux-firmware 1.143.1 SourcePackage: linux SystemImageInfo: current build number: 0 device name: channel: daily last update: Unknown UpgradeStatus: Upgraded to vivid on 2015-05-30 (0 days ago) dmi.bios.date: 08/28/2013 dmi.bios.vendor: Dell Inc. dmi.bios.version: A10 dmi.board.name: 0PJHXN dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: 0.1 dmi.modalias: dmi:bvnDellInc.:bvrA10:bd08/28/2013:svnDellInc.:pnXPSL322X:pvr:rvnDellInc.:rn0PJHXN:rvrA00:cvnDellInc.:ct8:cvr0.1: dmi.product.name: XPS L322X dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1460399/+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
