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From: Mike Dawson <mike.dawson@cloudapt.com>
To: Sahid Ferdjaoui <sahid.ferdjaoui@cloudwatt.com>, kvm@vger.kernel.org
Subject: Re: virtio: Large number of tcp connections, vhost_net seems to be a bottleneck
Date: Sun, 20 Oct 2013 11:52:36 -0400	[thread overview]
Message-ID: <5263FC44.5060001@cloudapt.com> (raw)
In-Reply-To: <533233212.1710860.1382256273232.JavaMail.root@cloudwatt.com>


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.
> --
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  reply	other threads:[~2013-10-20 15:52 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <7677902.1710678.1382256256542.JavaMail.root@cloudwatt.com>
2013-10-20  8:04 ` virtio: Large number of tcp connections, vhost_net seems to be a bottleneck Sahid Ferdjaoui
2013-10-20 15:52   ` Mike Dawson [this message]
2013-10-21  8:50     ` Sahid Ferdjaoui
2013-10-23 12:30   ` Jason Wang

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