[Mesa-dev] [PATCH 7/7] i965: Fix asynchronous mappings on !LLC platforms.

[Daniel Vetter]

On Thu, Jul 06, 2017 at 10:51:49PM -0700, Kenneth Graunke wrote:
> On Wednesday, July 5, 2017 2:24:55 PM PDT Chris Wilson wrote:
> > Quoting Kenneth Graunke (2017-07-05 21:56:54)
> > In the meantime, s/else if (!bo->cache_coherent)/if (!bo->cache_coherent)/
> 
> Oh?  I can do that.  I figured that when we asked the kernel to create a
> brand new CPU map for us, it would guarantee that the new virtual address
> range didn't have any stale data in the CPU caches.  But, if it doesn't,
> then we definitely need to clflush them out.

Caches are physically indexed, brand new mmap doesn't do anything with
them. The only exception is the gtt mmap, which for implementation reasons
cflushes the entire thing.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch