New fb-based DDX, performance regressions relative to xfree86

[Timothy Normand Miller]

2009/12/15 Timothy Normand Miller <theosib at gmail.com>:
> 2009/12/15 Michel Dänzer <michel at daenzer.net>:
>
>> If the old X server didn't have the damage layer yet, I suspect that
>> might account for some of the overhead... Profiling with sysprof or
>> oprofile might be interesting.
>
> Yeah.  I've noticed that.  And I'm encountering something strange.
> For wide PolyArc, I call miPolyArc, which decomposes the primitive
> into spans.  If the rop is GXcopy, then my DDX's FillSpans gets
> called.  If the rop is GXxor, it doesn't.  We're trying to figure out
> why that might be happening.  In the mean time, can anyone give me
> some insight into why my GC ops might get overridden?  I think
> fbPolyArc is getting called by damage.

Very interesting.  In miarc.c, look for fTricky.  It creates a 1-bit
pixmap, draws to that instead of making spans, and then calls
PushPixels.


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