[Intel-gfx] [PATCH 2/2] intel: Use I915_EXEC_NO_RELOC when available

[Daniel Vetter]

On Tue, Jan 20, 2015 at 10:10:57PM -0800, Kristian Høgsberg wrote:
> However, drm_intel_bo_reference/unreference() is showing up on the
> profiles now that relocations are cheaper, but I think the better way
> to make those cheaper is to move the ref count to the public struct
> and make the ref/unref inline functions (calling out to a destructor
> for the refcount==0 case, of course).  On that note, do you know why
> drm_intel_gem_bo_unreference() is so convoluted? What's the deal with
> the atomic_add_unless?

Smells like the last reference can only be dropped with the mutex held,
probably because someone is assuming that buffers don't go poof while
holding the mutex. You should be able to drop this after some refcounting
audit to make sure no one looks at a bo after the unref is done.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch