Poor compositing performance on 965Q chipset with intel 2.2.1 driver

[Barry Scott]

Marius Gedminas wrote:
> On Fri, May 09, 2008 at 07:39:47AM -0700, Keith Packard wrote:
>   
>> On Fri, 2008-05-09 at 14:11 +0100, Barry Scott wrote:
>>
>>     
>>> Using latest libpciaccess makes no difference MTRR status is the same:
>>>       
>> It's not the MTRRs that are broken, it's the page mapping which is
>> setting the ignore cache and write through bits on each page mapped by
>> libpciaccess. There's a kludge-around which takes advantage of a
>> different kernel bug to clear those bits. A simple test:
>>
>> $ x11perf -shmput500
>>
>> If that gives you a number significantly less than 1000, then your pages
>> are probably mis-mapped.
>>     
>
> Which number is that?  The # per second?
>
> mg at platonas:~ $ x11perf -shmput500
> x11perf - X11 performance program, version 1.5
> The X.Org Foundation server version 10400090 on :0.0
> from platonas
> Fri May  9 18:31:46 2008
>
> Sync time adjustment is 0.0309 msecs.
>
>    3200 reps @   1.6794 msec (   595.0/sec): ShmPutImage 500x500 square
>    3200 reps @   1.6568 msec (   604.0/sec): ShmPutImage 500x500 square
>    3200 reps @   1.7887 msec (   559.0/sec): ShmPutImage 500x500 square
>    3200 reps @   1.6947 msec (   590.0/sec): ShmPutImage 500x500 square
>    3200 reps @   1.6732 msec (   598.0/sec): ShmPutImage 500x500 square
>   16000 trep @   1.6986 msec (   589.0/sec): ShmPutImage 500x500 square
>
> This is with GM965 and intel driver 2.2.1, but I haven't noticed poor
> compositing performance.
>
> Marius Gedminas
>   
Try playing a movie full screen and look at the CPU used by Xorg. At 
1360x768
on a Due Core 2 CPU top says that Xorg is using 50%. On the 945 and Q35 
I see 2%.

Barry