em interface slow down on 8.0R

[John Nielsen]

On Dec 5, 2009, at 4:40 AM, Hiroki Sato <hrs at freebsd.org> wrote:

> Hiroki Sato <hrs at freebsd.org> wrote
>  in <20091203.182931.129751456.hrs at allbsd.org>:
>
> hr>  And another thing, I noticed a box with 82573E and 82573L  
> sometimes
> hr>  got stuck after upgrading to 8.0-STABLE.  It has moderate network
> hr>  load (average 5-10Mbps) on both NICs.  It worked for a day or  
> two and
> hr>  then got stuck suddenly.  Rebooting the box solved the  
> situation, but
> hr>  it got stuck again after a day or so.  After it happens, the
> hr>  interface does not respond.  The other functionalities of FreeBSD
> hr>  seemed working.  Doing an up/down cycle for the NICs seemed to  
> send
> hr>  some packets, but it did not recover completely; rebooting was  
> needed
> hr>  for recovery.  This box does not have the RTT problem.  I am  
> still
> hr>  not sure what is the trigger, there seems something wrong.
>
> Things turned out for this symptom so far are:
>
> - This occurs around once per 1-2 days.
>
> - Once it occurs, all of communications including ARP and IPv4 stop.
>
> - "ifconfig em0 down/up" can recover the interface. However, on doing
>   "up" after "down" the following message was displayed:
>
>   # ifconfig em0 up
>   em0: Could not setup receive structures
>
>   After trying it several times it worked.
>
>   Then, the interface seemed back to normal for a couple of minutes,
>   but it stopped again.
>
> I guess there is a kind of deadlock somewhere but not sure it is
> really related to the em(4) driver.  I will continue to investigate
> anyway.

I'm curious, what speed/duplex is your interface using and is it  
statically set or using autoselect?

JN