On Thu, 14 Apr 2011 10:03:45 +0100, Chris Wilson wrote: > The docs have a dire warning not to attempt to access snooped (the old > style of cache sharing on pre-SandyBridge chipsets) pages through the GTT. > Prevent userspace from doing so by sending them a SIGBUS if they try. There is not plan for the user mode driver to use snooped access on pre-SNB chipsets. So, the kernel should not try to support this in any way. -- keith.packard@intel.com