Xorg Uses at least 18% of the cpu

[Philip Walden]

Andras Simon wrote:
> On 2/5/07, Philip Walden <pwaldenlinux at pacbell.net> wrote:
>> Andras Simon wrote:
>> >
>> > Hmm. I'm using Xorg's nv driver,  not the Nvidia binary driver, and my
>> > Nvidia card is pretty old, so this may be totally irrelevant, but
>> > anyway:
>>
>> The driver should not matter. The MTRR gives the driver efficient access
>> to the AGP card.
>
> OK
>
>> >
>> > $ cat /proc/mtrr
>> > reg00: base=0x00000000 (   0MB), size= 512MB: write-back, count=1
>> > reg01: base=0xe0000000 (3584MB), size=  64MB: write-combining, count=1
>>
>> This *looks* like a decent MTRR setting although it would appear
>> incorrect for the lspci listing below
>>
>> reg01: base=0xd8000000 (?????MB), size=  128MB: write-combining, count=1
>> >
>> > $ /sbin/lspci -v
>> > ...
>> > VGA compatible controller: nVidia Corporation NV11 [GeForce2 MX/MX 
>> 400]
>> > (rev b2) (prog-if 00 [VGA])
>> >        Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 11
>> >        Memory at e4000000 (32-bit, non-prefetchable) [size=16M]
>> >        Memory at d8000000 (32-bit, prefetchable) [size=128M]
>> >
>> > Unless I misunderstood your explanation, this means that the mtrr
>> > settings are not correct. Still, Xorg's cpu utilization is 0.3% (all
>> > this on a PIII, FC5, with regularly updated Xorg server).
>
> So, based on the above, and your description, I guess I should
> echo "base=0xd8000000 size=0x8000000 type=write-combining" >| /proc/mtrr

That looks correct.

However, I am wondering where the other reg01 mttr is coming from:

reg01: base=0xe0000000 (3584MB), size=  64MB: write-combining, count=1
>
>> If Xorg is using only 0.3% cpu when doing intensive graphics/video (ie
>> mplayer, xine) then I think your MTRR is just fine.
>
> Well, no, not when under stress. It can easily go up to 50% when
> mplayer is running.
> The OP wrote
>
> | I have top running in a terminal window and there are two processes
> | running, Xorg and top. Xorg is using 18% of the cpu.
>
> so I assumed this thread was about Xorg cpu utilization when X is idle.