[PULL] MAXSCREENS removal preparation

[Jamey Sharp]

On Mon, Apr 26, 2010 at 9:27 AM, Aaron Plattner <aplattner at nvidia.com> wrote:
>> Jamey Sharp (3):
>>       xfree86: use screen privates for Xv offscreen images.
>
> Why does xf86XVRegisterOffscreenImages call dixRequestPrivate every time,
> with a constant size?  You should be able to call it in, say,
> xf86XVScreenInit and just rely on dixLookupPrivate to allocate the
> requested size for you.

I tried initializing the private record in xf86XVScreenInit, but
xf86XVRegisterOffscreenImages gets called before that, at least in
some drivers.

dixRequestPrivate is a no-op after the first call, so this just makes
it clear that the memory is definitely allocated (assuming you don't
call xf86XVQueryOffscreenImages without registering them first). I
don't see a problem for either performance or clarity here; can you
explain what you're objecting to?

>>       xfree86: use screen privates for exclusive DGA clients
>
> Can we ditch DGAClientPrivateKey and combine the two DGA keys into one?
> I'm worried that we're going to hit PRIV_MAX (currently 256) soon.

I thought about this. I think a separate patch to merge private keys
that are always used on different types of objects would be
worthwhile. This patch follows the existing convention though.

A quick check says there's something like 140 keys allocated anywhere
in the server source tree right now though, so I don't think this is a
big danger yet.

> Speaking of that, we should probably increase PRIV_MAX or make it dynamic
> somehow if we're going to move a lot of stuff to devPrivates.

It's an implementation detail of privates.c, so making it dynamic is
trivial, and I doubt the extra memory fetch per private access would
show up in any profiling.

Jamey