From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Ahern <dsahern@gmail.com>
Subject: Re: Kernel 4.19 network performance - forwarding/routing normal users
 traffic
Date: Thu, 1 Nov 2018 11:23:03 -0600
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Cc: netdev <netdev@vger.kernel.org>, Yoel Caspersen <yoel@kviknet.dk>
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On 11/1/18 7:52 AM, Paweł Staszewski wrote:
> 
> 
> W dniu 01.11.2018 o 11:55, Jesper Dangaard Brouer pisze:
>> On Wed, 31 Oct 2018 21:37:16 -0600 David Ahern <dsahern@gmail.com> wrote:
>>
>>> This is mainly a forwarding use case? Seems so based on the perf report.
>>> I suspect forwarding with XDP would show pretty good improvement.
>> Yes, significant performance improvements.
>>
>> Notice Davids talk: "Leveraging Kernel Tables with XDP"
>>   http://vger.kernel.org/lpc-networking2018.html#session-1
> It will be rly interesting

It's pushing the exact use case you have: FRR manages the FIB, XDP
programs get access to updates as they happen for fast path forwarding.

> 
>> It looks like that you are doing "pure" IP-routing, without any
>> iptables conntrack stuff (from your perf report data).  That will
>> actually be a really good use-case for accelerating this with XDP.
> Yes pure IP routing
> iptables used only for some local input filtering.
> 
> 
>>
>> I want you to understand the philosophy behind how David and I want
>> people to leverage XDP.  Think of XDP as a software offload layer for
>> the kernel network stack. Setup and use Linux kernel network stack, but
>> accelerate parts of it with XDP, e.g. the route FIB lookup.
>>
>> Sample code avail here:
>>  
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/samples/bpf/xdp_fwd_kern.c
>>
> I can try some tests on same hw but testlab configuration - will give it
> a try :)
> 

That version does not work with VLANs. I have patches for it but it
needs a bit more work before sending out. Perhaps I can get back to it
next week.