Re: virtio: Large number of tcp connections, vhost_net seems to be a bottleneck
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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: virtio: Large number of tcp connections, vhost_net seems to be a bottleneck
Thanks for your back Mike, I did some tests with ovs2.0 and the number of tcp connections up to 1 000 000 easily. So if I understand well the deal is not in relation with vhost_net or it can have a link between them? http://i.imgur.com/kJJWtOk.png s. - Original Message - From: Mike Dawson mike.daw...@cloudapt.com To: Sahid Ferdjaoui sahid.ferdja...@cloudwatt.com, kvm@vger.kernel.org Sent: Sunday, October 20, 2013 5:52:36 PM Subject: Re: virtio: Large number of tcp connections, vhost_net seems to be a bottleneck 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: virtio: Large number of tcp connections, vhost_net seems to be a bottleneck
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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
