Created attachment 244251 [details] A zip file of dmesg logs, the bisect log, ver_linux logs, lspci log, and two videos Hello, I noticed that in newer Linux 4.8 kernels the desktop was performing very poorly. Opening windows (such as xterm) takes a very long time, as does dragging windows around the screen and resizing. Alt-tab also has significant lag, with an exception being when switching between two fullscreen xterm windows. I am using IceWM as a window manager on Arch Linux. After doing a bisection, I found that the issue is not present in 194dc870 and is present on 554828ee, which does not touch the i915 driver directly (https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=554828ee0db41618d101d9549db8808af9fd9d65). The bisection was done using the following AUR package: https://aur.archlinux.org/packages/linux-git/ I have attached one video showing performance with the problem and one video showing performance without the problem, as well as dmesg and other logs. I'll be happy to provide more info to narrow down the problem. Here is the Arch Linux forums thread this is first mentioned in. https://bbs.archlinux.org/viewtopic.php?id=219349
Created attachment 244461 [details] git bisect log
Created attachment 244471 [details] Screen capture showing slowness Not visible, but there is significant delay (about 1 - 1.5 seconds) between the open terminal key shortcut and the terminal appearing.
Created attachment 244481 [details] Screen capture showing expected performance for comparison
Created attachment 244491 [details] dmesg after booting the bad kernel
Created attachment 244501 [details] dmesg after booting the good kernel
Created attachment 244511 [details] ver_linux output from bad kernel
Created attachment 244521 [details] ver_linux output from good kernel
Created attachment 244531 [details] lspci output
Please file drm/i915 bugs at https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel
https://bugs.freedesktop.org/show_bug.cgi?id=98755