From owner-svn-src-head@FreeBSD.ORG Fri Jul 18 18:15:28 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 4A6BA518; Fri, 18 Jul 2014 18:15:28 +0000 (UTC) Received: from mail-qg0-x232.google.com (mail-qg0-x232.google.com [IPv6:2607:f8b0:400d:c04::232]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id E91642F7B; Fri, 18 Jul 2014 18:15:27 +0000 (UTC) Received: by mail-qg0-f50.google.com with SMTP id q108so3452641qgd.23 for ; Fri, 18 Jul 2014 11:15:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=fjCBSkCzkm97nd51lQrUGAXz5XDrsUGWVtKnaN2sxN0=; b=naTpygt+T68PWgS5nxxMcOtwpFCC1X65yZdXp6VkAf6tXbXNRF5Iz5Hulkoxs1YDwi sm+7bP3PZ9qfBdd6poibQstsB7ZBMnN6gCcnh9zW4x7CM1D9IBPnq/ffkEdteQuhJj3v o5x+Y1A35ckOOFCU30tgFwNKMYSPFoHXxEEE4JlXCEPtq21WYIyI1olcAtSSgyyE3XLq HbYDz70N4FLjZh1NTyYZ2PS5HvJbdZHCJCC+vBn+bhvJ2IGZtLeXBMHArECDrHN4tKEh gFU7fJ6ZRlqzH3UTOUIpU7TJpCMGIMdYcIPtBQmydQL8HU/fPlRpBN1P+F5puPPd8QT0 Dt/w== MIME-Version: 1.0 X-Received: by 10.224.130.201 with SMTP id u9mr10816323qas.98.1405707324373; Fri, 18 Jul 2014 11:15:24 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.224.1.6 with HTTP; Fri, 18 Jul 2014 11:15:24 -0700 (PDT) In-Reply-To: <53C94F61.5020706@freebsd.org> References: <201407180822.s6I8MD5a023838@svn.freebsd.org> <53C94F61.5020706@freebsd.org> Date: Fri, 18 Jul 2014 11:15:24 -0700 X-Google-Sender-Auth: tgfd7Wglj9N46UC78_bzIGVbJ1c Message-ID: Subject: Re: svn commit: r268837 - head/sys/netinet From: Adrian Chadd To: Peter Grehan Content-Type: text/plain; charset=UTF-8 Cc: "svn-src-head@freebsd.org" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Jul 2014 18:15:28 -0000 On 18 July 2014 09:46, Peter Grehan wrote: >> Update the default RSS hash to the Chelsio T5 firmware one - it >> provides >> markedly better distribution of IPv6 address/ports than the previous >> key. > > > That's actually the key that's used for verification in the Microsoft spec, > though it looks like you have the bytes arranged backwards, which appears to > be an artifact of the strange way the key is programmed into the Chelsio. Hah! I wonder why the key from the T3 NIC that Robert committed was so .. terrible then. Are you saying that the actual byte order is totally reversed, or just endian? > My suggestion is: put the bytes in the default key in the order they are in > the spec. This allows independent verification of the hash function in > hardware by injecting frames with the values from the spec and looking at > what h/w provides. Then, fix how it is programmed in the Chelsio. From > memory, the Intel registers were a byte array. I also recall that the Qlogic > FCOE adapters were 32-bits at a time, but big-endian. Cool. > On the contents of the has, so long as there are a enough random 1-bits in > the key, the distribution is as good as the Jenkins hash. Easy to verify > with a test harness and ministat etc, but also verified at Netapp in the > mega performance lab with a number of different key values. I think that was Roberts main concern with using a randomised key at startup. It sounds Netapp have already done a lot of the work that I was thinking about in the back of my mind - I'll add that to my TODO list so we can write a random key generation function at boot time. Thanks1 -a