OK, 7 years after the original report, this issue still seems relevant on Ubuntu 20.04.
So how to know if a machine needs mtrr_cleanup at all? -- 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/1163587 Title: mtrr_cleanup: can not find optimal value, perhaps no longer needed? Status in linux package in Ubuntu: Triaged Bug description: The actual common error message from dmesg: [ 0.000000] original variable MTRRs [ 0.000000] reg 0, base: 0GB, range: 32GB, type WB [ 0.000000] reg 1, base: 3584MB, range: 512MB, type UC [ 0.000000] reg 2, base: 3548MB, range: 4MB, type UC [ 0.000000] reg 3, base: 3552MB, range: 32MB, type UC [ 0.000000] total RAM covered: 32220M [ 0.000000] gran_size: 64K chunk_size: 64K num_reg: 7 lose cover RAM: 28676M [ 0.000000] gran_size: 64K chunk_size: 128K num_reg: 7 lose cover RAM: 28676M [ 0.000000] gran_size: 64K chunk_size: 256K num_reg: 7 lose cover RAM: 28676M [ 0.000000] gran_size: 64K chunk_size: 512K num_reg: 7 lose cover RAM: 28676M [ 0.000000] gran_size: 64K chunk_size: 1M num_reg: 7 lose cover RAM: 28676M ... [ 0.000000] gran_size: 256M chunk_size: 2G num_reg: 6 lose cover RAM: 220M [ 0.000000] gran_size: 512M chunk_size: 512M num_reg: 5 lose cover RAM: 476M [ 0.000000] gran_size: 512M chunk_size: 1G num_reg: 5 lose cover RAM: 476M [ 0.000000] gran_size: 512M chunk_size: 2G num_reg: 5 lose cover RAM: 476M [ 0.000000] gran_size: 1G chunk_size: 1G num_reg: 5 lose cover RAM: 476M [ 0.000000] gran_size: 1G chunk_size: 2G num_reg: 5 lose cover RAM: 476M [ 0.000000] gran_size: 2G chunk_size: 2G num_reg: 4 lose cover RAM: 1500M [ 0.000000] mtrr_cleanup: can not find optimal value [ 0.000000] please specify mtrr_gran_size/mtrr_chunk_size I have found errors like this on many machines (one with 128 GB of RAM, mine with just 4GB). The instructions want you to specify kernel options that you don't need to do. Just turning off mtrr_cleanup appears to be the best option. You can fix it be specifying disable_mtrr_cleanup. According to kernel paramaters (https://www.kernel.org/doc/Documentation/kernel-parameters.txt) disable_mtrr_cleanup [X86] The kernel tries to adjust MTRR layout from continuous to discrete, to make X server driver able to add WB entry later. This parameter disables that. From this I understand it was here to help allow leave the X server space if it needed it in the future. That should no longer be necessary, correct? I have an Intel GPU and noticed no performance problems by disabling it. ProblemType: Bug DistroRelease: Ubuntu 13.04 Package: linux-image-3.8.0-16-generic 3.8.0-16.26 ProcVersionSignature: Ubuntu 3.8.0-16.26-generic 3.8.5 Uname: Linux 3.8.0-16-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.9.2-0ubuntu5 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: bryan 1978 F.... pulseaudio Date: Tue Apr 2 16:56:13 2013 EcryptfsInUse: Yes InstallationDate: Installed on 2013-02-04 (56 days ago) InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130204.1) MachineType: Dell Inc. Inspiron 1545 MarkForUpload: True ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-16-generic root=UUID=0983e077-6f15-4e52-a776-faa186229dc8 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.8.0-16-generic N/A linux-backports-modules-3.8.0-16-generic N/A linux-firmware 1.104 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/07/2009 dmi.bios.vendor: Dell Inc. dmi.bios.version: A14 dmi.board.name: 0G848F dmi.board.vendor: Dell Inc. dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvrA14:bd12/07/2009:svnDellInc.:pnInspiron1545:pvr:rvnDellInc.:rn0G848F:rvr:cvnDellInc.:ct8:cvr: dmi.product.name: Inspiron 1545 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1163587/+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
