From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH 6/7] mlx4_en: Adding rxhash support Date: Wed, 19 Oct 2011 15:57:08 +0100 Message-ID: <1319036228.2829.14.camel@bwh-desktop> References: <4E9C8D8B.90606@mellanox.co.il> <1318902525.2571.24.camel@edumazet-laptop> <953B660C027164448AE903364AC447D2235EEB65@MTLDAG01.mtl.com> <1318926870.2657.5.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <953B660C027164448AE903364AC447D2235EEC80@MTLDAG01.mtl.com> <20111018083606.6367ff50@nehalam.linuxnetplumber.net> <1318966500.2783.124.camel@bwh-desktop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Yevgeny Petrilin , Eric Dumazet , "davem@davemloft.net" , "netdev@vger.kernel.org" To: Stephen Hemminger Return-path: Received: from mail.solarflare.com ([216.237.3.220]:2242 "EHLO exchange.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755010Ab1JSO5M (ORCPT ); Wed, 19 Oct 2011 10:57:12 -0400 In-Reply-To: <1318966500.2783.124.camel@bwh-desktop> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 2011-10-18 at 20:35 +0100, Ben Hutchings wrote: [...] > There was also a proposal a while back that we should try to make the > hash symmetric w.r.t. RX and TX addresses, so that both directions of a > flow through a router/bridge are aligned. I think this was to be done > by repeating a 16-bit pattern across the key. Not sure whether that's > worthwhile. That also makes it relatively cheap to calculate in software, which DragonflyBSD does: http://gitweb.dragonflybsd.org/dragonfly.git/blob/master:/sys/net/toeplitz.c http://gitweb.dragonflybsd.org/dragonfly.git/blob/master:/sys/net/toeplitz2.h (the latter file appears to assume that in_addr_t/in_port_t are byte- swapped i.e. the host is little-endian). Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.