From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: linux-next network throughput performance regression Date: Fri, 6 Nov 2015 13:45:52 -0700 Message-ID: <563D1180.60206@cumulusnetworks.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: David Miller , KY Srinivasan , Haiyang Zhang To: Simon Xiao , "devel@linuxdriverproject.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.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?