On Tue, Jul 14, 2020 at 12:18 PM Maxim Mikityanskiy
<maximmi@xxxxxxxxxxxx> wrote:
>
> On 2020-07-10 17:16, Magnus Karlsson wrote:
> > Add support to share a umem between different devices. This mode
> > can be invoked with the XDP_SHARED_UMEM bind flag. Previously,
> > sharing was only supported within the same device. Note that when
> > sharing a umem between devices, just as in the case of sharing a
> > umem between queue ids, you need to create a fill ring and a
> > completion ring and tie them to the socket (with two setsockopts,
> > one for each ring) before you do the bind with the
> > XDP_SHARED_UMEM flag. This so that the single-producer
> > single-consumer semantics of the rings can be upheld.
>
> I'm not sure if you saw my comment under v1 asking about performance.
> Could you share what performance numbers (packet rate) you see when
> doing forwarding with xsk_fwd? I'm interested in:
>
> 1. Forwarding between two queues of the same netdev.
>
> 2. Forwarding between two netdevs.
>
> 3. xdpsock -l as the baseline.
Sorry for the delay Max, but it is all due to vacation. I will provide
you with the numbers once the weather turns sour and/or the family
gets tired of me ;-). From what I can remember, it did not scale
perfectly linearly, instead it hit some other bottleneck, though I did
not examine what at that time.
/Magnus
> Thanks,
> Max
>
> >
> > Signed-off-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
> > ---
> > net/xdp/xsk.c | 11 ++++-------
> > 1 file changed, 4 insertions(+), 7 deletions(-)
> >
> > diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
> > index 05fadd9..4bf47d3 100644
> > --- a/net/xdp/xsk.c
> > +++ b/net/xdp/xsk.c
> > @@ -695,14 +695,11 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> > sockfd_put(sock);
> > goto out_unlock;
> > }
> > - if (umem_xs->dev != dev) {
> > - err = -EINVAL;
> > - sockfd_put(sock);
> > - goto out_unlock;
> > - }
> >
> > - if (umem_xs->queue_id != qid) {
> > - /* Share the umem with another socket on another qid */
> > + if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
> > + /* Share the umem with another socket on another qid
> > + * and/or device.
> > + */
> > xs->pool = xp_create_and_assign_umem(xs,
> > umem_xs->umem);
> > if (!xs->pool) {
> >
>
