spin lock panic in 5.2-REL

So, the quad-Xeon box serving half of ftp.freebsd.org was upgraded to
5.2-RELEASE Sunday night, and a couple of hours ago it broke to gdb w/ a
spin lock panic.

-=-
spin lock sched lock held by 0x8d2f7a00 for > 5 seconds
   panic: spin lock held too long
   cpuid = 4;
   Debugger("panic")
   Stopped at      Debugger+0x55:  xchgl   %ebx,in_Debugger.0
   db>
   db>
   db>
   db> [tail-]
-=-

We had this issue after updating to 5.1-REL, one of our techs caught this
and reset the box to bring it back online, so I don't have any additional
info.  I am not sure if this is a revisit of those same problems, or if
it's something new.

Here is the kernel conf for your consideration:

-=-
include GENERIC

ident           ISC_DEBUG

maxusers        512

# Normal ISC goo...
options         IPFIREWALL
options         IPFIREWALL_VERBOSE      #print information about
options         IPFIREWALL_VERBOSE_LIMIT=100    #limit verbosity
options         IPFIREWALL_DEFAULT_TO_ACCEPT    #allow everything by
default
options         IPV6FIREWALL            #firewall for IPv6
options         IPV6FIREWALL_VERBOSE
options         IPV6FIREWALL_VERBOSE_LIMIT=100
options         IPV6FIREWALL_DEFAULT_TO_ACCEPT
options         IPDIVERT                #divert sockets
options         IPSTEALTH               #support for stealth forwarding
options         TCP_DROP_SYNFIN         #drop TCP packets with SYN+FIN
options         HZ=1000
#options        NMBCLUSTERS=32768
options         DUMMYNET

# Esp. for sf1
options         KVA_PAGES=512
options         VM_KMEM_SIZE_SCALE="4"
#options        VM_KMEM_SIZE_MAX="(1024*1024*1024)"
#options        VM_KMEM_SIZE_MAX="(512*1024*1024)"
#options        VM_KMEM_SIZE_MAX="(768*1024*1024)"

# Debugging foo
makeoptions     DEBUG=-g                #Build kernel with gdb(1) debug symbols
options         DDB                     #Enable the kernel debugger
#options        INVARIANTS              #Enable calls of extra sanity checking
#options        WITNESS                 #Enable checks to detect deadlocks and cycles
#options        WITNESS_SKIPSPIN        #Don't run witness on spinlocks for speed

options         ADAPTIVE_MUTEXES
#options                ZERO_COPY_SOCKETS
-=-

Thanks in advance for any suggestions -

-Peter
-- 
Peter_Losher_at_isc.org | ISC | OpenPGP 0xE8048D08 | "The bits must flow"