From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: Re: intel 82599 multi-port performance Date: Mon, 26 Sep 2011 09:04:59 -0700 Message-ID: <4E80A2AB.2040206@intel.com> References: <4E805359.2080600@gmail.com> <4E808A41.8040902@genband.com> <4E809D59.10103@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "J.Hwan.Kim" , netdev To: frog1120@gmail.com Return-path: Received: from mga11.intel.com ([192.55.52.93]:50910 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751472Ab1IZQE7 (ORCPT ); Mon, 26 Sep 2011 12:04:59 -0400 In-Reply-To: <4E809D59.10103@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 09/26/2011 08:42 AM, J.Hwan.Kim wrote: > On 2011=EB=85=84 09=EC=9B=94 26=EC=9D=BC 23:20, Chris Friesen wrote: >> On 09/26/2011 04:26 AM, J.Hwan Kim wrote: >>> Hi, everyone >>> >>> Now, I'm testing a network card including intel 82599. >>> In our experiment, with the driver modified with ixgbe and multi-po= rt >>> enabled, >> >> What do you mean by "modified with ixgbe and multi-port enabled"? Yo= u >> shouldn't need to do anything special to use both ports. >> >>> rx performance of each port with 10Gbps of 64bytes frame is >>> a half than when only 1 port is used. >> >> Sounds like a cpu limitation. What is your cpu usage? How are your >> interrupts routed? Are you using multiple rx queues? >> > > Our server is XEON 2.4GHz with 8 cores. > I'm using 4 RSS queues for each port and distributed it's interrupts=20 > to different cores respectively. > I checked the CPU utilization with TOP, I guess ,it is not cpu=20 > imitation problem. What kind of rates are you seeing on a single port versus multiple=20 ports? There are multiple possibilities in terms of what could be=20 limiting your performance. It sounds like you are using a single card, would that be correct? If=20 you are running close to line rate on both ports this could be causing=20 you to saturate the PCIe x8 link. If you have a second card available=20 you may want to try installing that in a secondary Gen2 PCIe slot and=20 seeing if you can improve the performance by using 2 PCIe slots instead= =20 of one. Also could you include your kernel config? Certain features such as=20 Netfilter and IOMMU can have a significant impact on performance. Thanks, Alex