Re: [kernel PATCH] drm/nouveau: add NOUVEAU_GEM_RELOC_HILO

[Marcin Slusarz <marcin.slusarz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Wed, Jan 12, 2011 at 10:08:55PM +0100, Francisco Jerez wrote:
> Marcin Slusarz <marcin.slusarz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:
> 
> > add new relocation flag which allows to halving number of relocation
> > entries on >= nv50 cards
> >
> I suspect that this change is unnecessary. If you're actually seeing a
> performance improvement (I guess you are?), it's very likely to be

I did it for performance reasons, but actual improvement is very small (0.3%).
I sent these patches, because it's just better to do less and use less memory.

> masking the actual root of the problem -- last time I checked the nv50
> gallium pipe driver was rather careless about reloc re-submission (it
> re-submits the whole reloc chain once for every draw call instead of
> once for every pushbuf flush), and nouveau_reloc_emit() and friends are
> very unoptimized.
> 
> I'm betting that using HILO or not will make pretty much no difference
> once those two places are fixed :).

It looks they are already fixed :).

Well, you can treat these patches as data (relocations are not a bottleneck)
and forget about them.

Marcin