On 06/23/2013 01:30 PM, Dave Airlie wrote:
Why do you care about performance when PAT is disabled?
breaking old boxes just because, is just going to get reverted when I get the first regression report that you broke old boxes.
Not "just because", but *if* the choice is between breaking old boxes and breaking new boxes I'll take the latter.
Andy Lutomirski just submitted a bunch of patches to clean up the DRM usage of mtrrs, they are in drm-next, afaik we no longer add them on PAT systems.
Fantastic news. No issue, then, and no need to break anything.
The only problem I see with having ioremap_wc() installing an MTRR on non-PAT, rather than pushing that into the drivers which is clearly not the right thing, is that we will need a hook to uninstall it when the mapping is destroyed.
-hpa