From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J.Hwan Kim" Subject: Re: intel 82599 multi-port performance Date: Tue, 27 Sep 2011 09:45:02 +0900 Message-ID: <4E811C8E.8020508@gmail.com> References: <4E805359.2080600@gmail.com> <4E808A41.8040902@genband.com> <4E809D59.10103@gmail.com> <4E80A2AB.2040206@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev To: Alexander Duyck Return-path: Received: from mail-pz0-f42.google.com ([209.85.210.42]:36333 "EHLO mail-pz0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750765Ab1I0ApI (ORCPT ); Mon, 26 Sep 2011 20:45:08 -0400 Received: by pzk1 with SMTP id 1so16070154pzk.1 for ; Mon, 26 Sep 2011 17:45:07 -0700 (PDT) In-Reply-To: <4E80A2AB.2040206@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: On 2011=EB=85=84 09=EC=9B=94 27=EC=9D=BC 01:04, Alexander Duyck wrote: > 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-p= ort >>>> enabled, >>> >>> What do you mean by "modified with ixgbe and multi-port enabled"? Y= ou >>> 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. > I tested the 10G - 64byte frames. With ixgbe-modified driver, in single port, 92% of packet received in=20 driver level and in 2 port we received around 42% packets. > It sounds like you are using a single card, would that be correct? Yes, I tested a single card with 2 ports. > If you are running close to line rate on both ports this could be=20 > causing you to saturate the PCIe x8 link. If you have a second card=20 > available you may want to try installing that in a secondary Gen2 PCI= e=20 > slot and seeing if you can improve the performance by using 2 PCIe=20 > slots instead of one. I tested it also, if it is tested with 2 card, it seems that the=20 performance of each port is almost same with a single port. (maximum=20 performance)