Synchronization framework

[Maarten Lankhorst]

Hey Erik,

Op 07-06-12 19:35, Erik Gilling schreef:
> On Thu, Jun 7, 2012 at 1:55 AM, Maarten Lankhorst
> <m.b.lankhorst at gmail.com> wrote:
>> I haven't looked at intel and amd, but from a quick glance
>> it seems like they already implement fencing too, so just
>> some way to synch up the fences on shared buffers seems
>> like it could benefit all graphics drivers and the whole
>> userspace synching could be done away with entirely.
> It's important to have some level of userspace API so that GPU
> generated graphics can participate in the graphics pipeline.  Think of
> the case where you have a software video codec streaming textures into
> the GPU.  It needs to know when the GPU is done with those textures so
> it can reuse the buffer.
>
In the graphics case this problem already has to be handled without
dma-buf, so adding any extra synchronization api for userspace
that is only used when the bo is shared is a waste.

I do agree you need some way to synch userspace though, but I
think adding a new api for userspace is not the way to go.

Cheers,
Maarten

PS: re-added cc's that seem to have fallen off from your mail.