From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: Low throughput in VMs using VxLAN Date: Mon, 24 Aug 2015 10:27:00 -0700 Message-ID: <55DB53E4.4010105@hp.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit To: Santosh R , netdev@vger.kernel.org, tom@herbertland.com Return-path: Received: from g9t5009.houston.hp.com ([15.240.92.67]:58790 "EHLO g9t5009.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751179AbbHXR1F (ORCPT ); Mon, 24 Aug 2015 13:27:05 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 08/24/2015 09:19 AM, Santosh R wrote: > Hi, > > Earlier I was seeing lower throughput in VMs using VxLan as GRO was > not happening in VM. > Tom Herbert suggested to use "vxlan: GRO support at tunnel layer" patch series. > With today's net-next (4.2.0-rc7) in host and VM, I could see GRO > happening for vxlan, macvtap and virtual interface in VM. > The throughput is still low between VMs (around 4Gbps compared to > 9Gbps without VxLAN). Out of curiosity, have you tried tweaking gro_flush_timeout (gro_flush_interval?) for the VMs eth interface? Say perhaps a value of 1000? (I'm assuming the VM is using virtio_net) Does the behaviour change if vhost-net is loaded into the host and used by the VM? rick jones For completeness, it would also be good to compare the likes of netperf TCP_RR between VxLAN and without.