Chris Ng, FWIW, there is a big chance that the issue you observed is ultimately caused by thermald depending on weakly specified behavior that is known to be processor-model-specific, and which we now know to be also microcode-level specific.
Please refer to bug #1480349, and remove thermald from your system. Don't run thermald on any Xeon boxes. Removing thermald has a good chance of fixing the issue you observed, as the modified Ubuntu version that detects and refuses to run on Xeon boxes had not yet been sucessfully backported to vivid-lts at the time I wrote this reply. A reboot is required after removing thermald, to ensure all processor MSRs are reset to firmware/kernel defaults. If you do test the new microcode with thermald removed, please drop us a note on this bug report. Other users find this bug report through Google, and the information would be helpful to them. If removing thermald does NOT fix your issue, I would really like to know about it to further try to debug this issue. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-lts-vivid in Ubuntu. https://bugs.launchpad.net/bugs/1506050 Title: intel cpu frequency is stuck at ~400mhz Status in linux-lts-vivid package in Ubuntu: Invalid Bug description: I upgraded an install of 14.0.4.3 to the LST Enablement Stack for Vivid (kernel 3.19) that is running on a Xeon E5-1630 V3 (a Haswell Quad-Core) . Booting with 3.19 would result in the system being very sluggish. 'cpupower frequency-info' would report that the CPU was running at around 400mhz, as would 'cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq'. The CPUs would remain around 400mhz regardless of load. This was using the intel_pstate driver and the powersave governor. Switching to the performance governor had no effect. Using the acpi- cpufreq driver also had no effect, the system was still sluggish even though the reported frequencies in /sys/devices/. Eventually I tracked it down to the original install having had the intel_microcode package installed at some point. Once I removed this then the CPU frequencies scaled correctly with load. FYI the particular version installed was intel-microcode/trusty-updates,now 2.20140624-t-1ubuntu2 amd64. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.19.0-30-generic 3.19.0-30.34~14.04.1 ProcVersionSignature: Ubuntu 3.19.0-30.34~14.04.1-generic 3.19.8-ckt6 Uname: Linux 3.19.0-30-generic x86_64 NonfreeKernelModules: nvidia zfs zunicode zcommon znvpair zavl ApportVersion: 2.14.1-0ubuntu3.15 Architecture: amd64 Date: Wed Oct 14 12:38:05 2015 InstallationDate: Installed on 2014-08-05 (434 days ago) InstallationMedia: Lubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2) SourcePackage: linux-lts-vivid UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-vivid/+bug/1506050/+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
