Ubuntu
linux package

  1. Bug #574733
  2. Comment #22

Comment 22 for bug 574733

Revision history for this message
Thomas Schlichter (bigboss77) wrote :

Hi,

I tested this kernel linked from https://wiki.ubuntu.com/KernelMainlineBuilds with lucid:
   linux-image-2.6.35-999-generic_2.6.35-999.201006021335_i386.deb

It does not contain vesafb but uvesafb module. So I tested uvesafb and it behaves just like the lucid kernel module. This means even though uvesafb adds write-combining MTRR entries it adds uncached-minus PAT entries. Therefore the openchrome driver cannot add overlapping write-combining PAT entries and also uses uncached-minus PAT entries. This results in the serve performance penalty exactly as described in my first post.

So no difference between lucid kernel and mainline kernel. I'll remove the 'needs-upstream-testing' tag.

Best regards,
  Thomas