[RFC 1/8] dma-buf/fence: add fence_collection fences

[Gustavo Padovan]

2016-04-15 Daniel Vetter <daniel at ffwll.ch>:

> On Fri, Apr 15, 2016 at 11:03 AM, Christian König
> <christian.koenig at amd.com> wrote:
> > Might be that how amdgpu uses the fence context and sequence number is a bit
> > questionable, but this will completely break it.
> 
> You mean it tries to qualesce fences in the same context down to just
> the last one? That's how it's supposed to be done, and
> fence_collections do break this somewhat. Without fixing up
> fence_is_later and friends. Sounds like amdgpu is a good use case to
> make sure the changes in semantics in these functions result in
> sensible code. In a way a fence_collection is a fence where the
> timeline never matches with any other timeline (since it's a
> combiation).
> 
> And yeah I think fence_collection should probably compress down the
> fences to 1 per timeline. But then that's just an implementation
> detail we can fix later on.

You mean asking for a new context for every collection?

	Gustavo