[PATCH] gl-renderer: Create a high priority context

[Daniel Stone]

Hi Chris,
wayland-devel@ rather than weston[sic]-dev[sic]@ ...

On Sat, 2018-01-20 at 00:39 +0000, Chris Wilson wrote:
> EGL_IMG_context_priority allows the client to request that their
> rendering be considered high priority. For ourselves, this is important
> as we are interactive and any delay in our rendering causes input-output
> jitter; a less than smooth user interactive. So if the driver supports
> setting the context priority, try and create our EGLContext as high
> priority. The driver may reject our request due to system restrictions,
> in which case it will fallback to normal priority, but if successful it
> will reschedule our rendering and all of its dependencies to execute
> earlier, especially important when the GPU is being hogged by background
> clients.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Stone <daniels at collabora.com>
> ---
> Note that in testing I found a regression in i965_dri.so,
> (see "i965: Accept CONTEXT_ATTRIB_PRIORITY for brwCreateContext")
> so bare that in mind if testing against Intel.

This looks good to me. My only trivial complaint is that failing to obtain
a high-priority context probably shouldn't be logged by default. However,
in the absence of any way to actually control logging verbosity, this
isn't your fault ...

I'd like the Mesa patch to land and sit for a month or so, to narrow the
odds that users are going to fail to start Weston. But once it's sat for a
bit, happy to land it and this is:
Reviewed-by: Daniel Stone <daniels at collabora.com>

Cheers,
Daniel