El Wed, 12 Dec 2007 00:31:18 +0100 Rene Herman <[EMAIL PROTECTED]> escribió:
> 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! > > Rene. On my AMD 3800 X2 (2000MHz) ULi M1697 2.6.24-rc5 i get: cycles: out 1844674407370808, in 1844674407369087 It is not constant but variations are not significant afaics -- 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/
