Poor compositing performance on 965Q chipset with intel 2.2.1 driver

[Barry Scott]

Michel Dänzer wrote:
> On Fri, 2008-05-09 at 18:35 +0300, 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.
>>     
>
> EXA in xserver 1.4 had a less optimized ShmPutImage implementation.
>
> I think the mystery could indeed just be due to the different 3D engines
> - the infamous issues covered by Carl Worth's blog posts only affect the
> 965 engine.
>
>   
Are you saying that there are accelerations that are done for the Q35 
and 945 that the 965Q cannot do?

Barry