ubuntu-x-swat team mailing list archive

["D. Hugh Redelmeier" <hugh@xxxxxxxxxx>]

I'm now using Ubuntu 9.04 on my x61t.

GLXgears now reports varying amounts in the range 900 to 1150 without
any mucking with MTRRs.  That suggests that the Intel X video driver now
uses the PAT mechanism.  Good!

The MTRRs are still overlapping.

I had to change mtrr-uncover to deal with a gratuitous change made to
the format of /proc/mtrr in kernel 2.6.28.  You can get the newer
version at ftp://ftp.cs.utoronto.ca/pub/hugh/mtrr-uncover-2009may13.tgz

Interestingly, fixing the MTRRs with mtrr-uncover and restarting X
seemed to make glxgears run consistently at about 900.  I have no idea
why.

Adding "enable_mtrr_cleanup" flag to the appropriate "kernel" line(s) in
your /boot/grub/menu.lst will also attempt to eliminate overlapping
MTRRs.  I don't know which Ubuntu kernel first included the cleanup code
but it is in Jaunty's 2.6.28.  On my system, the performance effect is
the same as if you used mtrr-uncover.  Of course it only operates at
boot time.

There have been obscure cases where mtrr-uncover worked and
enable_mtrr_cleanup did not.

-- 
MTRRs set up incorrectly with 4GB RAM -> X slow
https://bugs.launchpad.net/bugs/210780
You received this bug notification because you are a member of Ubuntu-X,
which is the registrant for xf86-video-intel.