Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755518AbZCNSPm (ORCPT ); Sat, 14 Mar 2009 14:15:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752525AbZCNSPb (ORCPT ); Sat, 14 Mar 2009 14:15:31 -0400 Received: from smtp-out.google.com ([216.239.33.17]:37988 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752486AbZCNSPa convert rfc822-to-8bit (ORCPT ); Sat, 14 Mar 2009 14:15:30 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding:x-system-of-record; b=YD0k4/gZChmz6e1ultCjry6D+NOrFbu2h3wSsLCKMiYaSwWdIeg2lAmcgyS8z28I1 U5Vo4Ow2xMTzfG33Y43mw== MIME-Version: 1.0 In-Reply-To: <20090313.191951.228619450.davem@davemloft.net> References: <65634d660903131459m645eb468y3ad850a1fd56d447@mail.gmail.com> <20090313.151913.21135937.davem@davemloft.net> <65634d660903131724s49009177pdc11005aa76a4b56@mail.gmail.com> <20090313.191951.228619450.davem@davemloft.net> Date: Sat, 14 Mar 2009 11:15:21 -0700 Message-ID: <65634d660903141115w7e164134ycece307f041e93a9@mail.gmail.com> Subject: Re: [RFC v2: Patch 1/3] net: hand off skb list to other cpu to submit to upper layer From: Tom Herbert To: David Miller Cc: 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 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1058 Lines: 23 On Fri, Mar 13, 2009 at 7:19 PM, David Miller wrote: > From: Tom Herbert > Date: Fri, 13 Mar 2009 17:24:10 -0700 > >> Enabling HW multi-queue has somewhat higher CPU >> utilization though, the extra device interrupt load is not coming for >> free. ?We actually use the HW multi-queue in conjunction with our >> software steering to get maximum pps (about 20% more). > > This is a non-intuitive observation. ?Using HW multiqueue should be > cheaper than doing it in software, right? > I suppose it may be counter-intuitive, but I am not making a general claim. I would only suggest that these software hacks could be a very good approximation or substitute for hardware functionality. This is a generic way to get more performance out of deficient or lower end NICs. -- 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/