On Wed, 12 Dec 2007 00:31:18 +0100 Rene Herman wrote: > 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. > > Posted a previous incarnation of this before, buried in the outb 0x80 thread > which had a serialising problem. This one should as far as I can see measure > the right thing though. Please yell if you disagree... > > For me, on a Duron 1300 (AMD756 chipset) I have a constant: > > [EMAIL PROTECTED]:~/src/port80$ su -c ./port80 > cycles: out 2400, in 2400 > > and on a PII 400 (Intel 440BX chipset) a constant: > > [EMAIL PROTECTED]:~/src/port80$ su -c ./port80 > cycles: out 553, in 251 > > Results are (mostly) independent of compiler optimisation, but testing with > an -O2 compile should be most useful. Thanks!
(-m32 build on x86_64) midway:/home/rddunlap/src # ./port80 cycles: out 2702, in 1903 midway:/home/rddunlap/src # ./port80 cycles: out 2688, in 1893 midway:/home/rddunlap/src # ./port80 cycles: out 2703, in 1909 midway:/home/rddunlap/src # ./port80 cycles: out 2687, in 1893 midway:/home/rddunlap/src # ./port80 cycles: out 2687, in 1893 midway:/home/rddunlap/src # ./port80 cycles: out 2701, in 1907 midway:/home/rddunlap/src # ./port80 cycles: out 2701, in 1919 midway:/home/rddunlap/src # ./port80 cycles: out 2687, in 1893 midway:/home/rddunlap/src # ./port80 cycles: out 2701, in 1909 midway:/home/rddunlap/src # ./port80 cycles: out 2706, in 1906 /proc/cpuinfo says CPU speed is processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 4 model name : Intel(R) Pentium(R) D CPU 3.00GHz stepping : 4 cpu MHz : 2999.988 --- ~Randy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
