9.2 ixgbe tx queue hang

[Christopher Forgeron]

(Pardon me, for some reason my gmail is sending on my cut-n-pastes if I cr
down too fast)

First set of logs:

Mar 21 11:07:00 SAN0 kernel: before pklen=65542 actl=65542 csum=4116
Mar 21 11:07:00 SAN0 kernel: after mbcnt=33 pklen=65542 actl=65542
Mar 21 11:07:00 SAN0 kernel: before pklen=65542 actl=65542 csum=4116
Mar 21 11:07:00 SAN0 kernel: after mbcnt=33 pklen=65542 actl=65542
Mar 21 11:07:00 SAN0 kernel: before pklen=65542 actl=65542 csum=4116
Mar 21 11:07:00 SAN0 kernel: after mbcnt=33 pklen=65542 actl=65542
Mar 21 11:07:00 SAN0 kernel: before pklen=65542 actl=65542 csum=4116
Mar 21 11:07:00 SAN0 kernel: after mbcnt=33 pklen=65542 actl=65542
Mar 21 11:07:00 SAN0 kernel: before pklen=65542 actl=65542 csum=4116

Here's a few later on.

Mar 21 11:10:09 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:10:09 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538
Mar 21 11:10:09 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:10:09 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538
Mar 21 11:10:09 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:10:09 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538
Mar 21 11:10:09 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:10:09 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538

Mar 21 11:23:00 SAN0 kernel: after mbcnt=33 pklen=65546 actl=65546
Mar 21 11:23:01 SAN0 kernel: before pklen=65546 actl=65546 csum=4116
Mar 21 11:23:01 SAN0 kernel: after mbcnt=33 pklen=65546 actl=65546
Mar 21 11:23:03 SAN0 kernel: before pklen=65546 actl=65546 csum=4116
Mar 21 11:23:03 SAN0 kernel: after mbcnt=33 pklen=65546 actl=65546
Mar 21 11:23:04 SAN0 kernel: before pklen=65546 actl=65546 csum=4116
Mar 21 11:23:04 SAN0 kernel: after mbcnt=33 pklen=65546 actl=65546

Mar 21 11:41:25 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:41:25 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538
Mar 21 11:41:25 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:41:25 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538
Mar 21 11:41:25 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:41:25 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538
Mar 21 11:41:25 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:41:25 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538
Mar 21 11:41:26 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:41:26 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538
Mar 21 11:41:26 SAN0 kernel: before pklen=65538 actl=65538 csum=4116
Mar 21 11:41:26 SAN0 kernel: after mbcnt=33 pklen=65538 actl=65538

To be clear, I changed tp->t_tsomax to IP_MAXPACKET at ~ 777 in
sys/netinet/tcp_output.c like so:

                        if (len > IP_MAXPACKET - hdrlen) {
                                len = IP_MAXPACKET - hdrlen;
                                sendalot = 1;
                        }

I notice there is more that is different between 9.1 and 10 for this file:
http://fxr.watson.org/fxr/diff/netinet/tcp_output.c?v=FREEBSD10;diffval=FREEBSD91;diffvar=v

I'm going to attempt inserting a 9.1 tcp_output.c and see if that makes any
difference.

Otherwise, I wait further ideas from the list.

Thanks.