[issue599] 1.9.0 reproducable panic

[Matthew Dillon]

:On Wed, Apr 11, 2007 at 11:38:48AM -0700, Matthew Dillon wrote:
:>=20
:>     Woa.  You mean the panic occurs only when you do the netstat -an comm=
:and
:>     under heavy network load?  It doesn't happen any other time?
:>=20
:
:Correct.  Once I execute "netstat -an" it panics.  Any ideas?
:
:--Peter

    That's really odd.  I looked at the code and found one possible
    place where the field could get out of whack.  Try turning off the
    tcp limited transmit code:

    (in /etc/sysctl.conf):
    net.inet.tcp.limitedtransmit=0

    and reboot to clean out any preexisting tcp connections (or otherwise
    clean them out manually by killing and restarting the services).

    I'm a bit at a loss a to why netstat -an would trigger the problem,
    though.  We do know that anything that accesses /dev/kmem heavily,
    like fstat, can crash the machine while chasing down stale pointers
    in kernel memory.  But this panic seems a bit at odds with the sort
    of crash I would expect from stale pointer chasing.

						-Matt