Quoting Ville Syrjälä (2018-09-11 14:07:18) > On Thu, Sep 06, 2018 at 08:01:43PM +0100, Chris Wilson wrote: > > Given that we are now reasonably confident in our ability to detect and > > reserve the stolen memory (physical memory reserved for graphics by the > > BIOS) for ourselves on most machines, we can put it to use. In this > > case, we need a page to hold the overlay registers. > > > > On an i915g running MythTv, H Buus noticed that > > > > commit 6a2c4232ece145d8b5a8f95f767bd6d0d2d2f2bb > > Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Date: Tue Nov 4 04:51:40 2014 -0800 > > drm/i915: Make the physical object coherent with GTT > > > > introduced stuttering into his video playback. After discarding the > > likely suspect of it being the physical cursor updates, we were left > > with the use of the phys object for the overlay. And lo, if we > > completely avoid using the phys object (allocated just once on module > > load!) by switching to stolen memory, the stuttering goes away. > > > > For lack of a better explanation, claim victory and kill two birds with > > one stone. > > A but peculiar. But looks fine to me. And we should have some > stolen pretty much everywhere. I guess my only concern is permanently > fragmenting stolen with this. Or does the allocator grab it from the > very end? Hmm, it using DRM_MM_INSERT_BEST for all atm. We can do better by using DRM_MM_INSERT_LOW for the permanent stuff, but at the beginning BEST should still be one-sided. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
