kern/111286: RELENG_6 em(4) watchdog timeout with IPSEC/mpsafenet

[Nathan Ferch]

>Number:         111286
>Category:       kern
>Synopsis:       RELENG_6 em(4) watchdog timeout with IPSEC/mpsafenet
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Apr 05 20:50:07 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Nathan Ferch
>Release:        6,2-RELEASE, 6.2-STABLE
>Organization:
>Environment:
FreeBSD threepwood 6.2-STABLE FreeBSD 6.2-STABLE #8: Thu Apr  5 12:40:54 CDT 2007     root at threepwood:/usr/obj/usr/src/sys/THREEPWOOD  i386
>Description:
I am getting frequent interface lockups and watchdog timeouts with em(4) when IPSEC is loaded with mpsafenet enabled or IPSEC is compiled into the kernel.

I have not been able to reproduce the problem with other interfaces.
>How-To-Repeat:
compile kernel:
+options                        IPSEC
+options                        IPSEC_ESP
+options                        IPSEC_DEBUG

generate network traffic:

nttcp -D  -l 65535 -T 10.129.0.2 (repeat until hang/watchdog timeout)

>Fix:
The watchdog timeout will usually reset the interface and allow operation after a few seconds.

In the case the watchdog timeout does not kick in, bringing the interface down then up will have the same effect.
>Release-Note:
>Audit-Trail:
>Unformatted: