On Sun, Aug 12, 2012 at 12:04:39PM +0100, Chris Wilson wrote: > In order to be able to ioremap_wc the GTT space, we need to remove the > conflicting pci_iomap from drm/i915, so we limit the register map in > drm/i915 to the suitable range for each generation. The benefit of doing > this is an order of magnitude reduction in time spent rewriting the GTT > entries when inserting and removing objects. For example, this halves the > CPU time spent in X when pushing pixels for chromium through a userptr > (chromium has a bug where it likes to recreate its ShmPixmap on every > draw). > > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk> How well does this work with ums? I guess if it blows up, we could ioremap uncached, but when kms initializes drop that uc mapping and try to remap wc. But I fear that ums will map the entire bar and hence we can't just unconditionally map the gatt wc. -Daniel -- Daniel Vetter Mail: daniel at ffwll.ch Mobile: +41 (0)79 365 57 48
