[Mesa-dev] [RFC] Linux Graphics Next: Explicit fences everywhere and no BO fences - initial proposal

[Simon Ser]

On Wednesday, April 28th, 2021 at 2:21 PM, Daniel Vetter <daniel at ffwll.ch> wrote:

> Yeah I think we have pretty clear consensus on that goal, just no one yet
> volunteered to get going with the winsys/wayland work to plumb drm_syncobj
> through, and the kernel/mesa work to make that optionally a userspace
> fence underneath. And it's for a sure a lot of work.

I'm interested in helping with the winsys/wayland bits, assuming the
following:

- We are pretty confident that drm_syncobj won't be superseded by
  something else in the near future. It seems to me like a lot of
  effort has gone into plumbing sync_file stuff all over, and it
  already needs replacing (I mean, it'll keep working, but we have a
  better replacement now. So compositors which have decided to ignore
  explicit sync for all this time won't have to do the work twice.)
- Plumbing drm_syncobj solves the synchronization issues with upcoming
  AMD hardware, and all of this works fine in cross-vendor multi-GPU
  setups.
- Someone is willing to spend a bit of time bearing with me and
  explaining how this all works. (I only know about sync_file for now,
  I'll start reading the Vulkan bits.)

Are these points something we can agree on?

Thanks,

Simon