Re: [net PATCH] i40e/i40evf: Limit TSO to 7 descriptors for payload instead of 8 per packet

On Wed, 2016-03-30 at 16:09 -0400, Sowmini Varadhan wrote:

On (03/30/16 12:41), Jesse Brandeburg wrote:

quoted

This gets "Even Uglier", I've turned off all offloads at my receiver,
enabled calling skb_linearize on *all* frames, which works fine for
scp, but the receiver shows > MSS sized frames on the wire for
rds-stress traffic.

fwiw, I was not able to reproduce this tx issue with iperf/netperf
etc either (I tried various perumtations of bidir, req-resp etc). One
difference between the rds-stress invocation and the other callers
is that this comes down via tcp_sendpage(), I dont know if there
is something in the sendpage path that i40e does not anticipate. 

You might try netperf -t TCP_SENDFILE -- -m 150

to let netperf use sendfile() on small frags.