Re: TCP/IP Checksumming

Matthias Urlichs (smurf@noris.de)
27 Nov 1996 23:37:38 +0100


In linux.dev.kernel, article <199611270135.UAA00826@neko.binary9.net>,
"Nicholas J. Leon" <lists-nicholas@binary9.net> writes:
>
> Heiko Schroeder was overheard whispering ...
> # OK, I just hacked a Linux version of a "test-suite" using the
> # cycle counter. (I'm using a Pentium Pro, so I can access the rdtsc
> # instruction in user code.)
> #
> # csum_partial: sum = 1a8a, min cycles 1406
> # csum_simple: sum = 1a8a, min cycles 6846
> # csum_c: sum = 1a8a, min cycles 2626
>
> csum_partial: sum = 1a8a, min cycles 674
> csum_simple: sum = 1a8a, min cycles 8219
> csum_c: sum = 1a8a, min cycles 3494
>
> This is on a 586/75. Could someone explain to me why the values would
> be so different than the before mentioned ones? For example, my

Umm, might the explanation be the difference between a 586 and a 686 ???

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