[cairo] Performance work update
cworth at cworth.org
Thu Aug 18 10:43:54 PDT 2005
On Mon Aug 15 11:12:13 2005, wrote:
> I put together a quick set of benchmarks for some cases I care about:
> compositing, line drawing, and image scaling (up and down).
Billy, thanks for putting this together!
Is there any reason this shouldn't go straight into CVS? I'll use my
creative naming skills to suggest a module location of:
> I'd like to hear feedback on what operations people are finding slow
> and maybe put together a more comprehensive set of benchmarks. Please
> email me if you have any ideas or code.
One idea that I think would be helpful is a way to run the suite of
tests and get some tabulated results. Maybe something with rows for
each test and columns for each backend. And hopefully a table small
enough to be easy to send back and forth in an email message, say.
> - I did an implementation of fbCompositeSrc_8888x8888mmx which makes
> my "over" test twice as fast.
> - I also found that mmxCombineMaskU and mmxCombineOverU missed special
> cases for 0 alpha and 0xff alpha. Adding those checks gave a 2x
> speedup for my line test.
Keep up the good work! Are these new things all in cairo already?
> - I am getting some strange results with Xfake. My "lines" test is
> slower (at least 50%) with the MMX code enabled than with it
> disabled. This is not reproducable with pixman + fbmmx, where the
> MMX code is much faster.
I have no insight on this one.
> - Some of the xlib paths with certain servers are terribly slow. With
> XFree86 4.3 on my Debian machine, the "over" test is 100x slower
> than the pixman version. I think we may need a better strategy for
> dealing with this problem.
I seem to recall Owen sending out an email not too long ago that
outlined a plan for dealing with the "old X server" problem. I can't
seem to find the mail now, but pieces of the plan involve deciding how
old an X server we should plan to support, and deciding whether the
right answer is to just always use the image backend rather than doing
some part-Render part-pixman approach.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 189 bytes
Desc: not available
Url : http://lists.freedesktop.org/archives/cairo/attachments/20050818/17ec0442/attachment-0001.pgp
More information about the cairo