Re: [Dri-devel] Re: ATI R200 PCI

[Ian R. <id...@us...>]

Roland Scheidegger wrote:
> Michel D=C3=A4nzer wrote:
>> On Thu, 2003-12-04 at 11:48, Mike A. Harris wrote:
>>
>>> THe first step to me, would be to oprofile things, and find where the=
=20
>>> bottleneck is, then try to determine why.
>>
>> Good idea, but beware that the gprof output was rather confusing when =
I
>> first saw this problem, the time would appear to be spent in random 3D
>> driver functions when in fact it seemed to be waiting for the hardware
>> most of the time. oprofile may do a better job there, but you've been
>> warned.
>=20
> Actually I did use oprofile when I did the AGP 1x and PCI gart tests=20
> (with an 9000pro AGP and forced PCI mode). I didn't submit the results=20
> because they looked uninteresting - glxgears still didn't use really=20
> much cpu time, it just was 10 times slower...
>=20
> oprofile agp 1x (not sure which parameters would be best to use with=20
> oprofile though):

You'll probably want to profile the kernel.  That's where the actual=20
hardware access happens, so that's likely to be the place where the=20
extra time is spent.  oporfile might also /not/ show anything useful.=20
If the extra time is spent waiting for an interrupt from the hardware,=20
it won't show up in CPU_CLK_UNHALTED time. :)