On Tue, Dec 14, 2021 at 01:09:01PM -0500, Tom Talpey wrote: > On 12/14/2021 12:29 PM, Jason Gunthorpe wrote: > > On Tue, Dec 14, 2021 at 12:27:24PM -0500, Tom Talpey wrote: > > > On 12/14/2021 12:42 AM, yanjun.zhu@xxxxxxxxx wrote: > > > > From: Zhu Yanjun <yanjun.zhu@xxxxxxxxx> > > > > > > > > Based on the link https://www.spinics.net/lists/linux-rdma/msg73735.html, > > > > get the source udp port number for a QP based on the local QPN. This > > > > provides a better spread of traffic across NIC RX queues. The method in > > > > the commit d3c04a3a6870 ("IB/rxe: vary the source udp port for receive > > > > scaling") is stable. So it is also adopted in this commit. > > > > > > > > Signed-off-by: Zhu Yanjun <yanjun.zhu@xxxxxxxxx> > > > > drivers/infiniband/hw/irdma/verbs.c | 7 ++++++- > > > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/infiniband/hw/irdma/verbs.c b/drivers/infiniband/hw/irdma/verbs.c > > > > index 102dc9342f2a..2697b40a539e 100644 > > > > +++ b/drivers/infiniband/hw/irdma/verbs.c > > > > @@ -690,6 +690,11 @@ static int irdma_cqp_create_qp_cmd(struct irdma_qp *iwqp) > > > > return status ? -ENOMEM : 0; > > > > } > > > > +static inline u16 irdma_get_src_port(struct irdma_qp *iwqp) > > > > +{ > > > > + return 0xc000 + (hash_32_generic(iwqp->ibqp.qp_num, 14) & 0x3fff); > > > > +} > > > > > > How do you ensure the resulting port number is not already in use? > > > > It doesn't matter, it is never used by anything, the receiver captures > > all data with the roce dport and ignores the sport > > It still violates core networking addressing principles, and will > mightily confuse a network capture that's filtering on source ports. > Firewalls, ICMP, and similar fabric behaviors may also interfere. Maybe, but most of that stuff doesn't work with roce anyhow. > SoftRoCE is forced to register/reserve the source port, isn't it? Logically it has to register the dest port, it receives from any source port. Due to the way the netstack works softroce can't do this trick either, IIRC. Jason
