Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763584AbZCNCHr (ORCPT ); Fri, 13 Mar 2009 22:07:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1765150AbZCNBxh (ORCPT ); Fri, 13 Mar 2009 21:53:37 -0400 Received: from one.firstfloor.org ([213.235.205.2]:34385 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765156AbZCNBxf (ORCPT ); Fri, 13 Mar 2009 21:53:35 -0400 Date: Sat, 14 Mar 2009 02:53:40 +0100 From: Andi Kleen To: Tom Herbert Cc: David Miller , yanmin_zhang@linux.intel.com, bhutchings@solarflare.com, andi@firstfloor.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, herbert@gondor.apana.org.au, jesse.brandeburg@intel.com, shemminger@vyatta.com Subject: Re: [RFC v2: Patch 1/3] net: hand off skb list to other cpu to submit to upper layer Message-ID: <20090314015340.GM11935@one.firstfloor.org> References: <65634d660903131358h765bef64y6a0f1b0db7400f6f@mail.gmail.com> <20090313.140217.143696945.davem@davemloft.net> <65634d660903131459m645eb468y3ad850a1fd56d447@mail.gmail.com> <20090313.151913.21135937.davem@davemloft.net> <65634d660903131724s49009177pdc11005aa76a4b56@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <65634d660903131724s49009177pdc11005aa76a4b56@mail.gmail.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 853 Lines: 21 > Yes, we are using a 10G NIC that supports multi-queue. The number of > RX queues supported is half the number of cores on our platform, so > that is going to limit the parallelism. With multi-queue turned on we The standard wisdom is that you don't necessarily need to transmit to each core, but rather to each shared mid or least level cache. Once the data is cache hot (or cache near) distributing it further in software is comparable cheap. So this means you don't necessarily need as many queues as cores, but more as many as big caches. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/