Re: [RFT] Port 0x80 I/O speed

From: Rene Herman
Date: Wed Dec 12 2007 - 09:32:37 EST


On 12-12-07 09:59, Juergen Beisert wrote:

$ for i in `seq 5`; do ./port80; sleep 1; done
cycles: out 5260, in 2372
cycles: out 5260, in 2384
cycles: out 5260, in 2323
cycles: out 5270, in 2382
cycles: out 5259, in 2323

$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 7
model name : Pentium III (Katmai)
stepping : 3
cpu MHz : 501.208

This one's really wrong. This would be 10 microsecs. I suppose the machine/bus was heavily loaded or something?

$ for i in `seq 5`; do ./port80; sleep 1; done
cycles: out 1214, in 1095
cycles: out 1215, in 1094
cycles: out 1214, in 1095
cycles: out 1216, in 1095
cycles: out 1213, in 1093

$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 11
model name : Intel(R) Celeron(TM) CPU 1000MHz

This one's normal again...

Rene.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/