From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: Re: virtio: Large number of tcp connections, vhost_net seems to be a bottleneck Date: Wed, 23 Oct 2013 20:30:44 +0800 Message-ID: <5267C174.5040407@redhat.com> References: <533233212.1710860.1382256273232.JavaMail.root@cloudwatt.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit To: Sahid Ferdjaoui , kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:29943 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753658Ab3JWMaz (ORCPT ); Wed, 23 Oct 2013 08:30:55 -0400 In-Reply-To: <533233212.1710860.1382256273232.JavaMail.root@cloudwatt.com> Sender: kvm-owner@vger.kernel.org List-ID: On 10/20/2013 04:04 PM, 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? You can if you enable the multiqueue support for virtio-net, it can use N threads when there's N queue pairs. See http://www.linux-kvm.org/page/Multiqueue for more information. > 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