I've been following these freeze issues since kernel 4.2. cstate is no longer as effective since 4.6-rc7+ and 4.5.4+.
The known relevant commits are (from bugzilla #109051): Freezing started after 3.16.7 with commit 31685c258e0b0ad6aa486c5ec001382cf8a64212 freezing worsened again between 4.1 and 4.2 with commit 8fb55197e64d5988ec57b54e973daeea72c3f2ff Reverting these commits in later kernels does not solve the problem. But for some users, it extends run time before the next freeze, sometimes substantially. intel_idle.max_cstate={0,1} has helped the most users the most, but it is a just a bandaid, not always effective. The most recent kernels have rendered the ..cstate argument ineffective. Other improvements in the kernel have reduced my freeze rate from < 30 minutes to about 10 hours. At those rates, it could take a month to bisect. Freezing only seems to occur on Intel processors (atom and later). The freeze rates vary widely from minutes to weeks. It has dependencies on the particular Intel processor & revision, the hardware platform and the kernel version. Linux distro does not seem to matter much. I have experienced freezes with Ubuntu, Mint, Manjaro, and Android_x86 on multiple platforms (Asus T100CHI & 2 Dell laptops) For me, cstate worked to prevent freezes until very recent kernels. As an intermittent problem, most freeze reports have been dismissed with "It's not in my arena". I believe this a cluster of problems requiring concurrent fixes. I'm not sure what Ubuntu can do to solve what seems to be obvious upstream kernel problems. Maybe Canonical can exert some influence on kernel.org to work on these freezes rather than breaking features that work while they push the bleeding edge outward. Many thousands of systems are affected, some of which belong to IT professions who influence equipment purchase and configuration for large corporations. An 18 month old fatal bug is a PR disaster waiting to happen. By fatal I mean that the freeze can irreparably corrupt an installed system (and I've had to re-install twice so far.) -- 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/1503731 Title: 8086:0f31 Ubuntu 15.04-15.10 freezes totally Status in linux package in Ubuntu: Incomplete Bug description: Ever since I first installed 15.04 back in April/May on my new DELL Inspiron 3646 I have experienced frequent(daily/every-other- day)complete lockups(cannot even switch to console(Alt-F1,F2,etc.). I have determined that the issue is related to the 'i915' driver in relation to my GPU. I'm currently using intel-linux-graphics- installer_1.2.0-0intel1_amd64.deb from https://01.org/linuxgraphics with similar results (maybe a little better than the stock i915 stack in 15.04). WORKAROUND: Use kernel boot parameter: intel_idle.max_cstate=1 I have gained _significant_ improvements in reliability / stability by using parameters in the i915 module: /etc/modprobe.d/i915.conf: options i915 semaphores=1 and / or /etc/default/grub: GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_pstate=disable" and / or /usr/share/X11/xorg.conf.d/20-intel.conf: Section "Device" Identifier "Intel Graphics" Driver "intel" Option "TearFree" "1" EndSection and / or Disable "Intel Virtualization Technologies" in the BIOS. ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: xorg (not installed) ProcVersionSignature: Ubuntu 3.19.0-30.34-generic 3.19.8-ckt6 Uname: Linux 3.19.0-30-generic x86_64 ApportVersion: 2.17.2-0ubuntu1.5 Architecture: amd64 CompositorRunning: None Date: Wed Oct 7 09:32:47 2015 DistUpgraded: Fresh install DistroCodename: vivid DistroVariant: ubuntu ExtraDebuggingInterest: Yes GraphicsCard: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Graphics & Display [8086:0f31] (rev 0e) (prog-if 00 [VGA controller]) Subsystem: Dell Device [1028:068d] InstallationDate: Installed on 2015-09-17 (19 days ago) InstallationMedia: Ubuntu-Server 15.04 "Vivid Vervet" - Release amd64 (20150422) LightdmGreeterLog: ** (lightdm-gtk-greeter:1005): WARNING **: [PIDs] Failed to execute command: upstart ** (lightdm-gtk-greeter:1005): WARNING **: Failed to load user image: Failed to open file '/home/chris/.face': No such file or directory MachineType: Dell Inc. Inspiron 3646 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-30-generic.efi.signed root=UUID=ef22be35-6f79-4356-be42-2689d1de0378 ro quiet SourcePackage: xorg UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev' UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 08/17/2015 dmi.bios.vendor: Dell Inc. dmi.bios.version: A09 dmi.board.name: 0V6D8J dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 3 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: A09 dmi.modalias: dmi:bvnDellInc.:bvrA09:bd08/17/2015:svnDellInc.:pnInspiron3646:pvr:rvnDellInc.:rn0V6D8J:rvrA00:cvnDellInc.:ct3:cvrA09: dmi.product.name: Inspiron 3646 dmi.sys.vendor: Dell Inc. version.compiz: compiz N/A version.ia32-libs: ia32-libs N/A version.libdrm2: libdrm2 2.4.60-2 version.libgl1-mesa-dri: libgl1-mesa-dri 10.5.9-2ubuntu1~vivid2 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 10.5.9-2ubuntu1~vivid2 version.xserver-xorg-core: xserver-xorg-core 2:1.17.1-0ubuntu3.1 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.0-1ubuntu2 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0-1ubuntu2 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917-1~exp1ubuntu2.2 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu2build1 xserver.bootTime: Tue Oct 6 20:05:51 2015 xserver.configfile: default xserver.errors: xserver.logfile: /var/log/Xorg.0.log xserver.outputs: product id 990 vendor ACR xserver.version: 2:1.17.1-0ubuntu3.1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1503731/+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