Messages in this thread | | | Date | Thu, 1 Jun 2006 01:11:25 -0600 | From | "Brian F. G. Bidulock" <> | Subject | Re: Question about tcp hash function tcp_hashfn() |
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Evgeniy,
On Thu, 01 Jun 2006, Evgeniy Polyakov wrote:
> On Thu, Jun 01, 2006 at 12:46:08AM -0600, Brian F. G. Bidulock (bidulock@openss7.org) wrote: > > > Since pseudo-randomness affects both folded and not folded hash > > > distribution, it can not end up in different results. > > > > Yes it would, so to rule out pseudo-random effects the pseudo- > > random number generator must be removed. > > > > > > > > You are right that having test with 2^48 values is really interesting, > > > but it will take ages on my test machine :) > > > > Try a usable subset; no pseudo-random number generator. > > I've run it for 2^30 - the same result: folded and not folded Jenkins > hash behave the same and still both results produce exactly the same > artifacts compared to XOR hash.
But not without the pseudo-random number generation... ?
> > Btw, XOR hash, as completely stateless, can be used to show how > Linux pseudo-random generator works for given subset - it's average of > distribution is very good.
But its distribution might auto-correlate with the Jenkins function. The only way to be sure is to remove the pseudo-random number generator.
Just try incrementing from, say, 10.0.0.0:10000 up, resetting port number to 10000 at 16000, and just incrementing the IP address when the port number wraps, instead of pseudo-random, through 2^30 loops for both. If the same artifacts emerge, I give in.
Can you show the same artifacts for jenkins_3word?
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