From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH NEXT 0/2] qlcnic: Add Qlogic 1/10Gb Ethernet driver for CNA devices Date: Tue, 05 Jan 2010 19:57:41 -0800 (PST) Message-ID: <20100105.195741.145481609.davem@davemloft.net> References: <7608421F3572AB4292BB2532AE89D5658B0BAE9471@AVEXMB1.qlogic.org> <20100105.163343.14826539.davem@davemloft.net> <4B43E872.5000809@hp.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: dhananjay.phadke@qlogic.com, shemminger@vyatta.com, amit.salecha@qlogic.com, netdev@vger.kernel.org To: rick.jones2@hp.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:52665 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755196Ab0AFD5g (ORCPT ); Tue, 5 Jan 2010 22:57:36 -0500 In-Reply-To: <4B43E872.5000809@hp.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Rick Jones Date: Tue, 05 Jan 2010 17:33:38 -0800 > David Miller wrote: >> From: Dhananjay Phadke >> Date: Tue, 5 Jan 2010 15:55:10 -0800 >> >>>The LRO you are talking about was still kernel based >>>LRO. Even GRO doesn't save PCIe transactions as much >>>HW LRO does. That is the key. The difference between >>>HW LRO and GRO is significant to keep former alive >>>for a while. > > Is it really the PCIe transactions (*)? ISTR that HW LRO also tended > to significantly cut-down on the ACK rate, rather like the oft-derided > ACK avoidance heuristics in Solaris, HP-UX and various MacOSX revs. Yes, it causes stretch ACKs, but so does GRO.