On Aug 20, Maciej Fijalkowski wrote:
> On Wed, Aug 19, 2020 at 03:13:48PM +0200, Lorenzo Bianconi wrote:
> > Update multi-buffer bit (mb) in xdp_buff to notify XDP/eBPF layer and
> > XDP remote drivers if this is a "non-linear" XDP buffer
> >
> > Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> > ---
> > drivers/net/ethernet/marvell/mvneta.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
> > index 832bbb8b05c8..36a3defa63fa 100644
> > --- a/drivers/net/ethernet/marvell/mvneta.c
> > +++ b/drivers/net/ethernet/marvell/mvneta.c
> > @@ -2170,11 +2170,14 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
> > struct bpf_prog *prog, struct xdp_buff *xdp,
> > u32 frame_sz, struct mvneta_stats *stats)
> > {
> > + struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> > unsigned int len, data_len, sync;
> > u32 ret, act;
> >
> > len = xdp->data_end - xdp->data_hard_start - pp->rx_offset_correction;
> > data_len = xdp->data_end - xdp->data;
> > +
> > + xdp->mb = !!sinfo->nr_frags;
>
> But this set is not utilizing it from BPF side in any way. Personally I
> would like to see this as a part of work where BPF program would actually
> be taught how to rely on xdp->mb. Especially after John's comment in other
> patch.
>
Sameeh is working on them. I did not include the patches since IMO they are
not strictly related to this series. I will include Sameeh's patches in v2.
Regards,
Lorenzo
> > act = bpf_prog_run_xdp(prog, xdp);
> >
> > /* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch */
> > --
> > 2.26.2
> >
>
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