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

[Bauke Jan Douma <bjdouma@xs4all.nl>]

Rene Herman wrote on 12-12-07 00:31:
> Good day.
> 
> Would some people on x86 (both 32 and 64) be kind enough to compile and 
> run the attached program? This is about testing how long I/O port access 
> to port 0x80 takes. It measures in CPU cycles so CPU speed is crucial in 
> reporting.

Compiled as you wished.
And here are the results from 10 iterations...:

cycles: out 1965, in 1263
cycles: out 1968, in 1251
cycles: out 1957, in 1257
cycles: out 1992, in 1253
cycles: out 1959, in 1248
cycles: out 1965, in 1264
cycles: out 1957, in 1256
cycles: out 1959, in 1248
cycles: out 1962, in 1298
cycles: out 1962, in 1275

Linux skyscraper 2.6.23.11 #1 SMP Sun Dec 16 11:54:12 CET 2007 i686 GNU/Linux

32bits system

processor       : 0
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stepping        : 7
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cache size      : 4096 KB
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wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr s
bogomips        : 4802.73
clflush size    : 64

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Core(TM)2 Quad CPU           @ 2.40GHz
stepping        : 7
cpu MHz         : 2400.182
cache size      : 4096 KB
physical id     : 0
siblings        : 4
core id         : 1
cpu cores       : 4
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr s
bogomips        : 10614.49
clflush size    : 64

processor       : 2
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Core(TM)2 Quad CPU           @ 2.40GHz
stepping        : 7
cpu MHz         : 2400.182
cache size      : 4096 KB
physical id     : 0
siblings        : 4
core id         : 2
cpu cores       : 4
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr s
bogomips        : 4800.17
clflush size    : 64

processor       : 3
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Core(TM)2 Quad CPU           @ 2.40GHz
stepping        : 7
cpu MHz         : 2400.182
cache size      : 4096 KB
physical id     : 0
siblings        : 4
core id         : 3
cpu cores       : 4
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr s
bogomips        : 4800.17
clflush size    : 64