Re: GSO with udp_tunnel_xmit_skb

From: Jason A. Donenfeld
Date: Fri Nov 06 2015 - 06:48:24 EST

Hi Tom,

On Fri, Nov 6, 2015 at 8:19 AM, Tom Herbert <tom@xxxxxxxxxxxxxxx> wrote:
> Is this about UFO or GSO (in email subject)? UFO should operate
> independently encapsulation or inner packet setting.

I suppose this is about UFO.

Specifically -- let's say I have a list of 500 skbs, which have their
data in place but don't yet have an IP or UDP header etc. I want to
send out these out using udp_tunnel_xmit_skb. Right now, if I just
send them all out, one after another, they don't seem to be getting
assembled into a super packet suitable for UFO. Instead, they're just
sent one at a time, and I get the vast majority of `perf top` CPU
usage in my ethernet card's driver and along the path to it -- the
problem that UFO is supposed to solve.

So my question is -- how can I make UFO happen with udp_tunnel_xmit_skb?

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