Bug 222775

Summary:	After re-enabling TSO, not seeing TSO pkts until restart iperf command
Product:	Base System	Reporter:	Bhargava Chenna. Marreddy <bhargava.marreddy>
Component:	kern	Assignee:	Eugene Grosbein <eugen>
Status:	Closed Not A Bug
Severity:	Affects Only Me	CC:	eugen
Priority:	---
Version:	CURRENT
Hardware:	Any
OS:	Any

Description Bhargava Chenna. Marreddy 2017-10-04 11:44:21 UTC

Staps to reproduce:-

1. Load if_bnxt driver
2. start iperf TCP traffic
3. Capture Tx pkts (command: tcpdump -i bnxt0), I can see > 60K lengh pkts.
4. Disable tso (command: ifconfig bnxt0 -tso)
5. Capture Tx pkts (command: tcpdump -i bnxt0).
   Max pkt length seen is 1440 (non-tso pkts)
6. Enable TSO (command: ifconfig bnxt0 -tso)
7. Capture Tx pkts (command: tcpdump -i bnxt0).
   Max pkt length seen is still 1440 (I was expecting TSO pkts here).
8. Terminate iperf sessions and start again.
   Now, I can see TSO pkts.

Can someone please confirm whether this is expected behavior? 
Why am I not able to see TSO pkts untill I re-start iperf session?

Comment 1 Eugene Grosbein freebsd_committer

2017-10-08 00:21:01 UTC

Bugzilla is not appropriate place to ask general questions, please direct this to forums or mailing list.