From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Dawson Subject: Re: virtio: Large number of tcp connections, vhost_net seems to be a bottleneck Date: Sun, 20 Oct 2013 11:52:36 -0400 Message-ID: <5263FC44.5060001@cloudapt.com> References: <533233212.1710860.1382256273232.JavaMail.root@cloudwatt.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit To: Sahid Ferdjaoui , kvm@vger.kernel.org Return-path: Received: from mail-ob0-f169.google.com ([209.85.214.169]:51873 "EHLO mail-ob0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751112Ab3JTPwj (ORCPT ); Sun, 20 Oct 2013 11:52:39 -0400 Received: by mail-ob0-f169.google.com with SMTP id wp4so4919865obc.0 for ; Sun, 20 Oct 2013 08:52:38 -0700 (PDT) In-Reply-To: <533233212.1710860.1382256273232.JavaMail.root@cloudwatt.com> Sender: kvm-owner@vger.kernel.org List-ID: On 10/20/2013 4:04 AM, Sahid Ferdjaoui wrote: > Hi all, > > I'm working on create a large number of tcp connections on a guest; > The environment is on OpenStack: > > Host (dedicated compute node): > OS/Kernel: Ubuntu/3.2 > Cpus: 24 > Mems: 128GB > > Guest (alone on the Host): > OS/Kernel: Ubuntu/3.2 > Cpus: 4 > Mems: 32GB > > Currently a guest can handle about 700 000 established connections, the cpus are not loaded and 12giga of memory are used. > I'm working to understand why I can go up... > > On my host, after several tests with different versions of openvswitch and with linux bridge, > It look like the process vhost_net is the only process loaded to 100% and it seems vhost_net cannot use more than 1 cpu. > > I would like to get more informations about vhost_net and if there is a solution to configure it to use more than 1 cpu? Not sure if it is relevant in your case, but the newly-released Open vSwitch 2.0 is now multi-threaded: http://openvswitch.org/releases/NEWS-2.0.0 @martin_casado said "This is a big deal. Multi-threading provides huge performance benefits on flow setup" https://twitter.com/martin_casado/status/390384030488616960 If you give it a try, let us know. - Mike > > Thanks a lot, > s. > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >