[openib-general] Re: [PATCH] repost: IPoIB queue size tune patch

[Michael S. Tsirkin]

Quoting r. Shirley Ma <xma at us.ibm.com>:
> IPoIB is not a real driver. Packets can be dropped from dev xmit queue to
> QPs send queue directly. Why we use tx_ring to induce overhead in
> send path?

As I see it, rx_ring and tx_ring are mostly to keep the dma mapping.
The fact that we have to track it implies I think a level of indirection
and since the number of these matches the qp size, it seems best to
allocate them at interface up and not dynamically.

But: by all means please go ahead and experiment: I was just trying to help with
these suggestions - I'll guess we'll see what you come up with.

In particular, lots of people recommend looking at NAPI as a way
to reduce iterrupt rate on receive.

-- 
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies