From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750737AbWFAHBq (ORCPT ); Thu, 1 Jun 2006 03:01:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750720AbWFAHBp (ORCPT ); Thu, 1 Jun 2006 03:01:45 -0400 Received: from relay.2ka.mipt.ru ([194.85.82.65]:9176 "EHLO 2ka.mipt.ru") by vger.kernel.org with ESMTP id S1750711AbWFAHBp (ORCPT ); Thu, 1 Jun 2006 03:01:45 -0400 Date: Thu, 1 Jun 2006 11:01:36 +0400 From: Evgeniy Polyakov To: David Miller , draghuram@rocketmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: Question about tcp hash function tcp_hashfn() Message-ID: <20060601070136.GA754@2ka.mipt.ru> References: <20060531090301.GA26782@2ka.mipt.ru> <20060531035124.B3065@openss7.org> <20060531105814.GB7806@2ka.mipt.ru> <20060531.114127.14356069.davem@davemloft.net> <20060601060424.GA28087@2ka.mipt.ru> <20060601001825.A21730@openss7.org> <20060601063012.GC28087@2ka.mipt.ru> <20060601004608.C21730@openss7.org> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <20060601004608.C21730@openss7.org> User-Agent: Mutt/1.5.9i X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.7.5 (2ka.mipt.ru [0.0.0.0]); Thu, 01 Jun 2006 11:01:38 +0400 (MSD) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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. 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. -- Evgeniy Polyakov