On 2020-12-01 22:42, Toke Høiland-Jørgensen wrote:
Björn Töpel <bjorn.topel@xxxxxxxxx> writes:
[...]
Performance up ~5% Mpps for the xdp_redirect_map and xdpsock samples,
and ~3% for bpf_redirect() programs.
Neat! Got actual numbers? :)
+~1 Mpps for AF_XDP, and +~3 Mpps for a naive (non-swapping) redirect.
[...]
This seems like an awful lot of copy-paste code reuse. Why not keep the
__xdp_map_lookup_elem() (and flags handling) in bpf_xdp_redirect_map()
and call this function after that lookup (using ri->tgt_value since
you're passing in ri anyway)? Similarly, __bpf_tx_xdp_map() already does
the disambiguation on map type for enqueue that you are duplicating here.
I realise there may be some performance benefit to the way this is
structured (assuming the compiler is not smart enough to optimise the
code into basically the same thing as this), but at the very least I'd
like to see the benefit quantified before accepting this level of code
duplication :)
Good points; I'll need to take this to the drawing board again. Please
refer to Alexei's reply.
Thanks for taking a look!
Björn
