Am Donnerstag, 16. April 2009 schrieb Brice Goglin: > PAT is disabled in 2.6.29, we feel like it may explain some performance > problems if the video memory isn't in write combining anymore.
Mh, I just checked my 2.6.26's image configuration, and it also seems to have PAT disabled: $ uname -a Linux Zweiblum 2.6.26-2-686 #1 SMP Thu Mar 26 01:08:11 UTC 2009 i686 GNU/Linux $ egrep '_PAT(_| )' < /boot/config-2.6.26-2-686 # CONFIG_X86_PAT is not set $ egrep '_PAT(_| )' < /boot/config-2.6.29-1-686 # CONFIG_X86_PAT is not set I diffed the Xorg.0.log with kernel 2.6.29 (extremely slow) and 2.6.26 (well usuable) and attached the results. Maybe the following "Failed to set tiling" are an indication of the problem - lines starting with "-" are from the 2.6.29 log, lines starting with "+" are from xorg running on 2.6.26: @@ -440,11 +440,14 @@ (**) intel(0): Tiling enabled (==) intel(0): VideoRam: 262144 KB (II) intel(0): Attempting memory allocation with tiled buffers. -(EE) intel(0): Failed to set tiling on front buffer: rejected by kernel -(EE) intel(0): Failed to set tiling on back buffer: rejected by kernel -(EE) intel(0): Failed to set tiling on depth buffer: rejected by kernel (II) intel(0): Tiled allocation successful. (II) intel(0): [drm] Registers = 0xdc100000 +(II) intel(0): [drm] ring buffer = 0xc0000000 +(II) intel(0): [drm] mapped front buffer at 0xc1000000, handle = 0xc1000000 +(II) intel(0): [drm] mapped back buffer at 0xc5000000, handle = 0xc5000000 +(II) intel(0): [drm] mapped depth buffer at 0xc6000000, handle = 0xc6000000 +(II) intel(0): [drm] mapped classic textures at 0xc7000000, handle = 0xc7000000 +(II) intel(0): [drm] Initialized kernel agp heap manager, 33554432 (II) intel(0): [dri] visual configs initialized (II) intel(0): vgaHWGetIOBase: hwp->IOBase is 0x03d0, hwp->PIOOffset is 0x0000 (**) intel(0): Option "MigrationHeuristic" "greedy" @@ -458,32 +461,35 @@ Greetings, Gunter
xorg_log_linux_2.6.29_2.6.26.diff.gz
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