From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Borkmann <daniel@iogearbox.net>
Subject: Re: [bpf-next V2 PATCH 0/2] Implement sample code for XDP cpumap
 IP-pair load-balancing
Date: Fri, 10 Aug 2018 16:10:20 +0200
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        Daniel Borkmann <borkmann@iogearbox.net>,
        Alexei Starovoitov <alexei.starovoitov@gmail.com>,
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To: Jesper Dangaard Brouer <brouer@redhat.com>, netdev@vger.kernel.org
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On 08/10/2018 02:02 PM, Jesper Dangaard Brouer wrote:
> Background: cpumap moves the SKB allocation out of the driver code,
> and instead allocate it on the remote CPU, and invokes the regular
> kernel network stack with the newly allocated SKB.
> 
> The idea behind the XDP CPU redirect feature, is to use XDP as a
> load-balancer step in-front of regular kernel network stack.  But the
> current sample code does not provide a good example of this.  Part of
> the reason is that, I have implemented this as part of Suricata XDP
> load-balancer.
> 
> Given this is the most frequent feature request I get.  This patchset
> implement the same XDP load-balancing as Suricata does, which is a
> symmetric hash based on the IP-pairs + L4-protocol.
> 
> The expected setup for the use-case is to reduce the number of NIC RX
> queues via ethtool (as XDP can handle more per core), and via
> smp_affinity assign these RX queues to a set of CPUs, which will be
> handling RX packets.  The CPUs that runs the regular network stack is
> supplied to the sample xdp_redirect_cpu tool by specifying
> the --cpu option multiple times on the cmdline.
> 
> I do note that cpumap SKB creation is not feature complete yet, and
> more work is coming.  E.g. given GRO is not implemented yet, do expect
> TCP workloads to be slower.  My measurements do indicate UDP workloads
> are faster.

Applied to bpf-next, thanks Jesper!