From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] NET: Multiqueue network device support. Date: Wed, 27 Jun 2007 17:31:39 -0700 (PDT) Message-ID: <20070627.173139.83620684.davem@davemloft.net> References: <1182983565.5155.12.camel@localhost> <20070627.155457.35508432.davem@davemloft.net> <1182989747.5155.89.camel@localhost> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: yi.zhu@intel.com, kaber@trash.net, peter.p.waskiewicz.jr@intel.com, netdev@vger.kernel.org, jeff@garzik.org, auke-jan.h.kok@intel.com To: hadi@cyberus.ca Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:47323 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1763762AbXF1AbU (ORCPT ); Wed, 27 Jun 2007 20:31:20 -0400 In-Reply-To: <1182989747.5155.89.camel@localhost> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: jamal Date: Wed, 27 Jun 2007 20:15:47 -0400 > On Wed, 2007-27-06 at 15:54 -0700, David Miller wrote: > > > The thing that's really important is that the value is not so > > large such that the TX ring can become empty. > > In the case of batching, varying the values makes a difference. > The logic is that if you can tune it so that the driver takes > "sufficiently long" to stay closed the more packets you accumulate at > the qdisc and the more you can batch to the driver (when it opens up). > Deciding what "sufficiently long" is an art - and i am sure speed > dependent. With e1000 at gige 128 seems to be a good value, going above > or below that gave lesser performance. Right. And another thing you want to moderate is lock hold times, perhaps even at the slight expense of performance.