RE: [PATCH 7/9] IB/core: generic RDMA READ/WRITE API

Steve Wise
2016-03-01T15:44:50Z

> >> + if (rdma_rw_use_mr(qp->device, port_num)) {
> >> + ret = rdma_rw_init_mr_wrs(ctx, qp, port_num, sg, sg_offset,
> >> + remote_addr, rkey, dir);
> >
> > At some point I would like the iWARP IO to do no-mr for WRITE/dma_nents
> > == 1, and WRITE/dma_nents <= max_send_sge for the device. I think this
> > will help smaller iSER/NVMEF READ IOPs. I'm testing this out now on the
> > NVMEF code, which is slightly different. If it proves out to better the
> > performance, I'll post a follow-on patch...
>
> Is this possible given that pd->local_dma_lkey has only local
> permissions?

The source of an RDMA WRITE doesn't need remote permissions.