[ofa-general] [PATCH RFCv2 1/2] RDMA: Add protocol statistics attributes to the RDMA sysfs.

[Roland Dreier]

 > This patch adds a sysfs attribute group called "proto_stats" under
 > /sys/class/infiniband/$device/ and populates this group with protocol
 > statistics if they exist for a given device.  Currently, only iWARP
 > stats are defined, but the code is designed to allow Infiniband protocol
 > stats if they become available.  These stats are per-device and more
 > importantly -not- per port.

Making this per-device makes sense I guess given that protocol
processing is not bound to a port -- ie in IB we have alternate path
migration that can make things switch ports, and for iWARP RNICs
presumably an offloaded connection could migrate from one port to
another if routing changes (although I doubt we have in-kernel support
for this).  And I would guess in most HW implementations, the
transport-handling logic has no idea what physical port the packets it's
working on is attached to.

However I see that iw_nes has an ethtool stat for "Retransmission
count", which is per-netdev and hence attached to a physical port.  Is
this a compromise to work with ethool, or is this really per-port for
nes devices?  How does Steve's approach work for you?

 - R.