Re: [RFC PATCH v2 0/5] eBPF RSS support for virtio-net

[Jason Wang <jasowang@redhat.com>]

On 2020/11/27 下午2:06, Yuri Benditovich wrote:
>
>
>     > After some experiments we can see that stripping of debug sections
>     > reduces the size of
>     > ELF from ~45K to ~20K (we tried to strip more but the libbpf
>     fails to
>     > load it, libbpf needs BTF and symbols)
>     > So I suggest to reevaluate the necessity of libbpf.
>     > For this specific BPF it does not present advantage and we
>     hardly can
>     > create some reusable code
>     > related to libbpf, i.e. any further BPF will need its own libbpf
>     wrapper.
>     > The BTF is really good feature and in case some later BPF will
>     need an
>     > access to kernel
>     > structures it will use libbpf loader.
>     > What you think about it?
>
>
>     If we can find a way to use BTF without libbpf, it should be
>     acceptable.
>
> But the point is that the RSS BPF does not need the BTF as it does not 
> use any kernel structures.


Kinds of, it tries to access skb. But yes, it doesn't access any 
metadata of skb.


> When we have, for example, filter BPF that will need the BTF - we'll  
> use libbpf for it.
> Anyway we do not have here any infrastructural code related to libbpf,


Right, so I think we can probably start from a non BTF version without 
libbpf. And adding other features on top.

Thanks