kernel-packages team mailing list archive

["Christopher M. Penalver" <christopher.m.penalver@xxxxxxxxx>]

Mika Fischer, this bug was reported a while ago and there hasn't been
any activity in it recently. We were wondering if this is still an
issue? If so, could you please test for this with the latest development
release of Ubuntu? ISO images are available from
http://cdimage.ubuntu.com/daily-live/current/ .

If it remains an issue, could you please run the following command in
the development release from a Terminal
(Applications->Accessories->Terminal), as it will automatically gather
and attach updated debug information to this report:

apport-collect -p linux <replace-with-bug-number>

Also, could you please test the latest upstream kernel available following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Please do not test the daily folder, but the one all the way at the bottom. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-v3.11

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

Once testing of the upstream kernel is complete, please mark this bug's
Status as Confirmed. Please let us know your results. Thank you for your
understanding.

** Tags removed: q45
** Tags added: hardy needs-kernel-logs needs-upstream-testing

** Changed in: linux (Ubuntu)
       Status: Triaged => Incomplete

-- 
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/210780

Title:
  MTRRs set up incorrectly with 4GB RAM -> X slow

Status in The Linux Kernel:
  Fix Released
Status in X.org xf86-video-intel:
  Won't Fix
Status in “linux” package in Ubuntu:
  Incomplete
Status in “xserver-xorg-video-intel” package in Ubuntu:
  Invalid

Bug description:
  After upgrading my Laptop to 4GB RAM my MTRRs are set up in such a way
  that X can't set up a write-combining range for the video memory
  anymore, causing a noticable loss of performance

  /proc/mtrr with 2GB:
  reg00: base=0x00000000 (   0MB), size=2048MB: write-back, count=1
  reg01: base=0x7f700000 (2039MB), size=   1MB: uncachable, count=1
  reg02: base=0x7f800000 (2040MB), size=   8MB: uncachable, count=1
  reg03: base=0xd0000000 (3328MB), size= 256MB: write-combining, count=1
  (last range added by X server)

  /proc/mtrr with 4GB:
  reg00: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1
  reg01: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
  reg02: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
  reg03: base=0xbf700000 (3063MB), size=   1MB: uncachable, count=1
  reg04: base=0xbf800000 (3064MB), size=   8MB: uncachable, count=1

  The video memory is at 0xd0000000 (256MB). Note that this range is
  already included in reg00 and reg01, so the X server cannot set up a
  write-combining range.

  If I manually fix the ranges to look like this:
  reg00: base=0xc0000000 (3072MB), size= 256MB: uncachable, count=1
  reg01: base=0x00000000 (   0MB), size=2048MB: write-back, count=1
  reg02: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
  reg03: base=0xbf700000 (3063MB), size=   1MB: uncachable, count=1
  reg04: base=0xbf800000 (3064MB), size=   8MB: uncachable, count=1
  reg05: base=0x80000000 (2048MB), size=1024MB: write-back, count=1
  reg06: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1

  , i.e. explicitly excluding 0xd0000000 (256MB) from both problematic ranges, then the X server can set up the write-combining range again:
  reg00: base=0xc0000000 (3072MB), size= 256MB: uncachable, count=1
  reg01: base=0x00000000 (   0MB), size=2048MB: write-back, count=1
  reg02: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
  reg03: base=0xbf700000 (3063MB), size=   1MB: uncachable, count=1
  reg04: base=0xbf800000 (3064MB), size=   8MB: uncachable, count=1
  reg05: base=0x80000000 (2048MB), size=1024MB: write-back, count=1
  reg06: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1
  reg07: base=0xd0000000 (3328MB), size= 256MB: write-combining, count=1
  (last range added by X server)

  I'm not sure who is responsible for the MTRRs, BIOS or kernel or both.
  In case of a broken BIOS, maybe the kernel can sanitize them anyway.

  Original description:
  -----
  Binary package hint: xserver-xorg-video-intel

  Today I upgraded my RAM from 1GB to 4GB. Everything worked fine but I
  noticed that scrolling in Firefox and dragging windows is noticeably
  slower than before. I checked this again by removing 2GB and got the
  same results (i.e. 2GB -> fast scrolling, 4GB -> slower scrolling)

  I suspect it has to do with this line from the X server:
  (WW) intel(0): Failed to set up write-combining range (0xd0000000,0x10000000)

  If this is something the kernel is responsible for, please feel free
  to reassign accordingly.

  I have no options in my BIOS to change anything that might be relevant
  to this (memory mapping, etc.)

  This is a Samsung Q45 with Intel X3100 graphics.

  I'll attach more debug info.

  ProblemType: Bug
  Architecture: i386
  Date: Wed Apr  2 14:18:58 2008
  DistroRelease: Ubuntu 8.04
  Package: xserver-xorg-video-intel 2:2.2.1-1ubuntu6
  PackageArchitecture: i386
  ProcEnviron:
   SHELL=/bin/bash
   PATH=/home/username/bin:/home/username/bin:/home/username/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
   LANG=de_DE.UTF-8
  SourcePackage: xserver-xorg-video-intel
  Uname: Linux 2.6.24-12-server i686

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/210780/+subscriptions