[Open-graphics] HELP: Weird discrepancy between fbZPutImage and memcpy

[Timothy Normand Miller]

On 7/11/07, Stephen Warren <swarren at wwwdotorg.org> wrote:
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> Timothy Normand Miller wrote:
> > Note:  We looked at it with a PCI bus analyzer, and what we see is
> > that the x.org code results in long bursts, while ours results in
> > individual transactions, which would explain why we're so slow.  What
> > could x.org code be doing that would result in bursts, while ours
> > doesn't?
>
> Probably, the dcache generates bursts during write-back/flush and CPU
> generates single-beat accesses when writing to uncached areas (or
> write-through cache?)

Is there something you can do when mapping memory that will set
whether it's cached or not?  We're just doing a simple mmap in our
test software, while we're using some xf86 function in the X server.


-- 
Timothy Normand Miller
http://www.cse.ohio-state.edu/~millerti
Open Graphics Project