Re: [PATCH net-next v2 0/5] bpf: BPF for lightweight tunnel encapsulation

On 1 November 2016 at 17:07, Tom Herbert [off-list ref] wrote:

On the other hand, I'm not really sure how to implement for this level
of performance this in LWT+BPF either. It seems like one way to do
that would be to create a program each destination and set it each
host. As you point out would create a million different programs which
doesn't seem manageable. I don't think the BPF map works either since
that implies we need a lookup (?). It seems like what we need is one
program but allow it to be parameterized with per destination
information saved in the route (LWT structure).

Attaching different BPF programs to millions of unique dsts doesn't
make any sense. That will obivously will never scale and it's not
supposed to scale. This is meant to be used for prefixes which
represent a series of endpoints, f.e. all local containers, all
non-internal traffic, all vpn traffic, etc. I'm also not sure why we
are talking about ILA here, you have written a native implementation,
why would you want to solve it with BPF again?

If you want to run a single program for all dsts, feel free to run the
same BPF program for each dst. Nobody is forcing you to attach
individual programs.