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From: Eric Dumazet <eric.dumazet@gmail.com>
To: James Yonan <james@openvpn.net>
Cc: netdev <netdev@vger.kernel.org>
Subject: Re: GSO/GRO and UDP performance
Date: Wed, 04 Sep 2013 04:53:51 -0700	[thread overview]
Message-ID: <1378295631.7360.98.camel@edumazet-glaptop> (raw)
In-Reply-To: <52270659.1090208@openvpn.net>

On Wed, 2013-09-04 at 04:07 -0600, James Yonan wrote:

> The bundle of UDP packets would traverse the stack as a unit until it 
> reaches the socket layer, where recvmmsg could pass the whole bundle up 
> to userspace in a single transaction (or recvmsg could disaggregate the 
> bundle and pass each datagram individually).

That would require a lot of work, say in netfilter, but also in core
network stack in forwarding, and all UDP users (L2TP, vxlan).

Very unlikely to happen IMHO.

I suspect the performance is coming from aggregation done in user space,
then re-injected into the kernel ?

You could use a kernel module, using udp_encap_enable() and friends.

Check vxlan_socket_create() for an example

  reply	other threads:[~2013-09-04 11:53 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-04 10:07 GSO/GRO and UDP performance James Yonan
2013-09-04 11:53 ` Eric Dumazet [this message]
2013-09-06  9:22   ` James Yonan
2013-09-06 13:07     ` Eric Dumazet
2013-09-06 16:42       ` Rick Jones
2013-09-06 19:26         ` James Yonan
2013-09-06 19:32           ` Eric Dumazet

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