Re: [PATCH] fixes to drm-next - TTM DMA code (v1)

[Thomas Hellstrom]

On 12/13/2011 05:07 PM, Jerome Glisse wrote:
> On Mon, Dec 12, 2011 at 03:09:26PM -0500, Konrad Rzeszutek Wilk wrote:
>    
> > Jerome pointed me to some accounting error in the DMA API debugging code and
> > while I can't figure it out yet, I did notice some extreme slowness - which
> > is due to the nouveau driver calling the unpopulate (now that unbind +
> > unpopulate are squashed) quite a lot (this is using Gnome Shell - I think GNOME2
> > did not have those issues but I can't recall).
> >
> > Anyhow these patches fix the 50% perf regression I saw and also some minor bugs
> > that I noticed.
> >
> >      
> Gonna review those today and test them.
>
> Cheers,
> Jerome
>    
Hi!

I'm not whether any drivers are still using the AGP backend?
Calling unpopulate / (previous clear) each time unbind is done should be 
quite
inefficient with that one, as AGP sets up its own data structures and 
copies page tables
on each populate. That should really be avoided unless there is a good 
reason to have it.

/Thomas


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