From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033760AbbKFUqB (ORCPT ); Fri, 6 Nov 2015 15:46:01 -0500 Received: from mail-io0-f180.google.com ([209.85.223.180]:34933 "EHLO mail-io0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031159AbbKFUp4 (ORCPT ); Fri, 6 Nov 2015 15:45:56 -0500 Subject: Re: linux-next network throughput performance regression To: Simon Xiao , "devel@linuxdriverproject.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: Cc: David Miller , KY Srinivasan , Haiyang Zhang From: David Ahern Message-ID: <563D1180.60206@cumulusnetworks.com> Date: Fri, 6 Nov 2015 13:45:52 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/6/15 1:31 PM, Simon Xiao wrote: > I compared the network throughput performance on SLES12 bare metal servers, between SLES12 default kernel and latest linux-next (2015-11-05) kernel, based on the test results, I suspect there is a network regression exists on Linux-Next over the 40G Ethernet network: > a) iperf3 reports 50% performance drop with single TCP stream on latest linux-next; > b) iperf3 reports 10% ~ 30% performance drop with 2 to 128 TCP streams on latest linux-next; > Another throughput benchmarking tool (ntttcp-for-linux) test result is also listed at the end of the email for reference. > Can you post your kernel config file?