Hi

From: Thomas Monjalon

10/08/2019 23:31, Thomas Monjalon:

quoted

06/08/2019 20:17, Andrew Rybchenko:

quoted

On 8/6/19 5:56 PM, Matan Azrad wrote:

quoted

The API breakage is because the ``tso_segsz`` field was documented
for LRO.

The ``tso_segsz`` field in mbuf indicates the size of each segment
in the LRO packet in Rx path and should be provided by the LRO
packet port.

While the generic LRO packet may aggregate different segments
sizes in one packet, it is impossible to expose this information
for each segment by one field and it doesn't make sense to expose
all the segments sizes in the mbuf.

A new field may be added as union with the above field to expose
the number of segments aggregated in the LRO packet.

Signed-off-by: Matan Azrad <redacted>
---

--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
+* mbuf: Remove ``tso_segsz`` mbuf field providing for LRO
+support. Use union
+  block for the field memory to be shared with a new field
+``lro_segs_n``
+  indicates the number of segments aggregated in the LRO packet.

I think that the number of segments is more logical in the case of LRO.
The question (already asked by Konstantin) is why it is needed at
all (statistics?). If so, it still makes sense.

Segment size is misleading here, since not all segments could be the
same size. So,

Acked-by: Andrew Rybchenko <redacted>

As far as I can see bnxt and qede do not fill it in.
mlx5 and vmxnet3 have the number of segments (vmxnet3 has segment
size sometimes and sometimes use a function to guess the value).
So both will win from the change.
It looks like virtio does not have number of segments. CC Maxime to
comment.

I support improving the API for LRO.
Unfortunately, the consensus is not strong enough at the moment.

We had no progress about LRO field in mbuf.
Is it a change we would like to have in 20.11?

+1 to make the change.