From: Eric Dumazet <eric.dumazet@gmail.com>
To: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Emmanuel Jeanvoine <emmanuel.jeanvoine@inria.fr>, netdev@vger.kernel.org
Subject: Re: Poor TCP bandwidth between network namespaces
Date: Fri, 08 Feb 2013 17:33:38 -0800 [thread overview]
Message-ID: <1360373618.6696.2.camel@edumazet-glaptop> (raw)
In-Reply-To: <20130204225227.GC6898@order.stressinduktion.org>
On Mon, 2013-02-04 at 23:52 +0100, Hannes Frederic Sowa wrote:
> On Mon, Feb 04, 2013 at 03:43:20PM +0100, Emmanuel Jeanvoine wrote:
> > I'm wondering why the overhead is so high when performing TCP
> > transfers between two network namespaces. Do you have any idea about
> > this issue? And possibly, how to increase the bandwidth (without
> > modifying the MTU on the veths) between network namespaces?
>
> You could try Eric's patch (already in net-next) and have a look at the rest
> of the discussion:
>
> http://article.gmane.org/gmane.linux.network/253589
Another thing to consider is the default MTU value :
65536 for lo, and 1500 for veth
It easily explains half performance for veth
One another thing is the tx-nocache-copy setting, this can explain some
extra percents.
next prev parent reply other threads:[~2013-02-09 1:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-04 14:43 Poor TCP bandwidth between network namespaces Emmanuel Jeanvoine
2013-02-04 22:52 ` Hannes Frederic Sowa
2013-02-09 1:33 ` Eric Dumazet [this message]
2013-02-09 1:54 ` Rick Jones
2013-02-09 2:17 ` Eric Dumazet
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