ATI 6.12.4 on ultraSparc runs slow
Michel Dänzer
michel at daenzer.net
Wed Mar 24 00:21:47 PDT 2010
On Mit, 2010-03-24 at 00:41 +0100, jean-francois simon wrote:
> 2010/3/24 Michel Dänzer <michel at daenzer.net>
>
>
> >
> > so i am assuming that most of the work is done by some X
> server
> > "painting code" to the shadowfb in system ram, which is then
> DMA'ed to
> > the scan out buffer in the GPU VRAM.
>
>
> It's only DMA'ed if you implemented that. ;)
>
> so it is PIO not DMA? just curious, where is the code that is doing
> that transfer?
shadowUpdatePacked() in xserver/miext/shadow/shpacked.c .
> > since i see a big difference between solaris/sparc and
> linux/x86-64,
> > one idea that comes to mind is that there could some
> overhead due to
> > the difference in endianess between the solaris and the
> linux box.
>
>
> I don't think that matters here, we can use GPU facilities to
> handle
> endianness for direct CPU access to the framebuffer.
>
>
> sorry i dont understand what you mean. are you saying i should no
> longer use shadowfb?
No, just that the code copying from the shadow buffer to VRAM doesn't
need to do anything about endianness.
--
Earthling Michel Dänzer | http://www.vmware.com
Libre software enthusiast | Debian, X and DRI developer
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