[Mesa-dev] [PATCH mesa 0/7] remove upstreamed specs

[Adam Jackson]

On Thu, 2017-11-23 at 16:32 +0000, Emil Velikov wrote:
> On 23 November 2017 at 16:04, Eric Engestrom <eric.engestrom at imgtec.com> wrote:
> > On Thursday, 2017-11-23 13:32:47 +0000, Emil Velikov wrote:
> > > 
> > > > - GLX_MESA_release_buffers
> > > 
> > > Extension is implemented only for Xlib based libGL. The DRI codepath
> > > has a TODO for at least 7 years.
> > > Worth checking if anyone uses it and not just deprecate the extension?
> > 
> > I don't know much about GLX, so I'll let someone else do this.
> 
> Ack. in the interim, can you grep your systems for any existing users?
> Looking from the opposite end - quick search shows that only Mesa has
> implemented the said extensions.

I'm not surprised. The issue that extension tries to address is by far
most painful for the xlib backend (and dri-swrast I suppose). For
actual direct rendering the ancillary buffers are owned by the window
system, the only client-side "memory leak" is the drawable's entry in
the hash table. And honestly who cares, by the time your drawable is
destroyed from under you you're probably about to exit anyway.

Personally I don't see a lot of value in the xlib backend, but someone
clearly does since we have two copies of it now (src/mesa/drivers/x11 
and src/gallium/state_trackers/glx/xlib). So I don't know if I'd call
the extension Obsolete, but I'd probably discourage anyone from caring
about it, if you need it you're already in a deeply non-performant code
path.

- ajax