No kernel change. Basically changes to /etc/default/grub are used when running update-grub to create the grub configuration. Leaving GRUB_TERM=console commented out causes grub to initialize some higher resolution graphics framebuffer mode. And (not quite sure) it might be that about some point in time this changed to be a higher resolution.
But looking at the two dmesg outputs you posted (possibly you have both kernels installed on the same box, so grub setup is the same in both cases just the newer kernel ends up being slower) shows both vesafb get initialized nearly identical. So right now its hard to say why things go so much slower in the newer kernels. The simple framebuffer imo should not be so much different in how it works. Cannot say why that works faster. simplefb might just be one of them. There is a whole bunch blacklisted in /etc/modprobe.d/blacklist-framebuffer.conf because they tend to cause issues. One other detail I noticed in the dmesg output was that the newer kernel managed to initialize local ipmi drivers. Not sure how much this is actually needed. As long as its not required to have access to ipmi directly (not lan) one can disable ipmi_si and dev_ipmi can be disabled in /etc/default/openipmi. Just mentioning that since console usually can be accessed via ipmi and maybe there is some kind of interference. -- 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/1434581 Title: Console extremely slow with 3.13 and newer kernels for certified servers with Matrox G200er2 or similar Status in linux package in Ubuntu: Confirmed Status in linux source package in Trusty: Confirmed Status in linux source package in Utopic: Confirmed Status in linux source package in Vivid: Confirmed Bug description: When I first came across this issue I thought it was the same as bug #1316035 (https://bugs.launchpad.net/ubuntu/+source/xorg- server/+bug/1316035), but this bug seems to be about X and it is reporting xorg-server as the package with the issue. I've seen a report on the certification program already on this, but it was lacking follow-up and suggested a bug report, question 255332 (https://answers.launchpad.net/ubuntu-certification/+question/255332). I've already asked about this on the forums, and received no replies. I originally encountered this issue due to having a bunch of Dell servers that I was testing with kernel 3.13 on 12.04. The text console is so slow that it is unusable when using vi or doing an operation similar to dpkg -l |grep xorg. Comparing the exact same system with kernel 3.2 or 3.11 loaded and running lsmod, vesafb is listed and performance is excellent. It is not listed on the 3.13 system. The same issue exists on 14.04 with the 3.13 or 3.16 kernel. Attempting to do modprobe vesa or modprobe vesafb returns modprobe: FATAL: Module vesa not found and modprobe: FATAL: Module vesafb not found respectively. Attempting to use uvesafb on this hardware results in a black screen. Attempting to use vga16fb results in good performance, but I am locked to 640x480. I tried to use fbset to force higher resolutions, but it either results in a distorted display or tells me there is not enough memory. I need a 1280x1024 console with performance equal to 12.04 with kernels 3.2-3.11. The server I'm using for testing is a Dell R320. This appears to be regression as I can duplicate it by simply doing a fresh install of 12.04.1 and not having the issue, while doing a fresh install of 12.04.5, 14.04.1, or 14.04.2 results in a very slow console. --- AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Mar 20 13:17 seq crw-rw---- 1 root audio 116, 33 Mar 20 13:17 timer AplayDevices: Error: [Errno 2] No such file or directory ApportVersion: 2.14.1-0ubuntu3.7 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: Error: [Errno 2] No such file or directory DistroRelease: Ubuntu 14.04 HibernationDevice: RESUME=UUID=3255aa87-ba68-4b74-bdb0-1112aba7d46e InstallationDate: Installed on 2015-03-20 (0 days ago) InstallationMedia: Ubuntu-Server 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.3) IwConfig: Error: [Errno 2] No such file or directory MachineType: Dell Inc. PowerEdge R320 Package: linux (not installed) PciMultimedia: ProcEnviron: TERM=linux PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-46-generic root=UUID=fda4445f-efe2-4e93-9adb-ecaf6386f8cd ro consoleblank=0 ProcVersionSignature: Ubuntu 3.13.0-46.79-generic 3.13.11-ckt15 RelatedPackageVersions: linux-restricted-modules-3.13.0-46-generic N/A linux-backports-modules-3.13.0-46-generic N/A linux-firmware 1.127.11 RfKill: Error: [Errno 2] No such file or directory Tags: trusty Uname: Linux 3.13.0-46-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: root _MarkForUpload: True dmi.bios.date: 09/23/2013 dmi.bios.vendor: Dell Inc. dmi.bios.version: 2.0.21 dmi.board.name: 0R5KP9 dmi.board.vendor: Dell Inc. dmi.board.version: A09 dmi.chassis.type: 23 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr2.0.21:bd09/23/2013:svnDellInc.:pnPowerEdgeR320:pvr:rvnDellInc.:rn0R5KP9:rvrA09:cvnDellInc.:ct23:cvr: dmi.product.name: PowerEdge R320 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1434581/+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
