Shared semaphores for amdgpu

[Dave Airlie]

On 9 March 2017 at 17:38, Christian König <christian.koenig at amd.com> wrote:
>> I do wonder if we need the separate sem signal/wait interface, I think
>> we should just add
>> semaphore chunks to the CS interface.
>
> Yeah, that's what I've said as well from the very first beginning.
>
> Another question is if we should really create another implementation to
> share semaphores between processes.
>
> In other words putting the current fences inside the semaphore into a
> sync_file with the signal_on_any bit set would have pretty much the same
> effect, except that the resulting object then had the sync_file semantics
> for adding new fences and can be used in the atomic IOCTLs as well.

So the vulkan external semaphore spec has two different type of semaphore
semantics, I'm not sure the sync_file semantics match the first type,
only the second.


I think we would still need separate objects to do the first type,
which I want for VR stuff..

I'll try and think about it a bit harder tomorrow.

Dave.