From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: [PATCH] NET: Multiqueue network device support. Date: Wed, 27 Jun 2007 20:15:47 -0400 Message-ID: <1182989747.5155.89.camel@localhost> References: <1182864448.5186.34.camel@localhost> <20070626.135756.30187055.davem@davemloft.net> <1182983565.5155.12.camel@localhost> <20070627.155457.35508432.davem@davemloft.net> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain 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: David Miller Return-path: Received: from wx-out-0506.google.com ([66.249.82.237]:28034 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752289AbXF1APv (ORCPT ); Wed, 27 Jun 2007 20:15:51 -0400 Received: by wx-out-0506.google.com with SMTP id h31so347875wxd for ; Wed, 27 Jun 2007 17:15:51 -0700 (PDT) In-Reply-To: <20070627.155457.35508432.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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. cheers, jamal