On Tue, Oct 22, 2019 at 12:35 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote:
>
> Björn Töpel <bjorn.topel@xxxxxxxxx> writes:
>
> > From: Björn Töpel <bjorn.topel@xxxxxxxxx>
> >
> > In commit 43e74c0267a3 ("bpf_xdp_redirect_map: Perform map lookup in
> > eBPF helper") the bpf_redirect_map() helper learned to do map lookup,
> > which means that the explicit lookup in the XDP program for AF_XDP is
> > not needed for post-5.3 kernels.
> >
> > This commit adds the implicit map lookup with default action, which
> > improves the performance for the "rx_drop" [1] scenario with ~4%.
> >
> > For pre-5.3 kernels, the bpf_redirect_map() returns XDP_ABORTED, and a
> > fallback path for backward compatibility is entered, where explicit
> > lookup is still performed. This means a slight regression for older
> > kernels (an additional bpf_redirect_map() call), but I consider that a
> > fair punishment for users not upgrading their kernels. ;-)
> >
> > v1->v2: Backward compatibility (Toke) [2]
> > v2->v3: Avoid masking/zero-extension by using JMP32 [3]
> >
> > [1] # xdpsock -i eth0 -z -r
> > [2] https://lore.kernel.org/bpf/87pnirb3dc.fsf@xxxxxxx/
> > [3] https://lore.kernel.org/bpf/87v9sip0i8.fsf@xxxxxxx/
> >
> > Suggested-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
> > Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
>
> Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Applied. Thanks
