Re: Performance drop on XDrawRectangles()

Chris Wilson
2014-01-08T18:09:58Z

On Wed, Jan 08, 2014 at 06:49:40PM +0100, Thomas Richter wrote:
> On 01/08/2014 06:10 PM, Chris Wilson wrote:
> >On Wed, Jan 08, 2014 at 04:57:52PM +0100, Thomas Richter wrote:
> >I've taken a quick look at this on an ivb i7-3270qm, and see a 296kops/s
> >to 248kops/s decrease. Not massive, and considering the difference in
> >our hardware probably a distinct issue.
>
> Well, note that a 1Ghz P-III / i830M is not an i7-3270qm. (-;
>
> Did you made the changes in x11perf as I did? The bottleneck is not
> in the actual rectangle rendering, it is somewhere in the call-path
> from the application down to the hardware, i.e. the per-call
> overhead increased by a factor of eight.

Yes, I'm using the modified one rect per request test.

> Kernel configuration is identical, as much as I could arrange it.
> X11 and higher level libraries are all identical, I only changed the
> kernel.

Same. But there are a lot of factors that changed for my two kernels
(FBC, ppgtt) to name but two which should not apply to your machine.
Anyway it looks like the bisect progressing smoothly here, so I'll find
out if there is something outside of i915.ko that changed. Later, I'll
poke around on i845g as well.