Deadlock, exclusive sx so_rcv_sx, amd64

Hello.

Running rtorrent and ftp brings my system to a deadlock
in a few hours. Kernel still responds to pings and sends some
TCP acks.

The kernel is from fresh RELENG_7, userland is from 'CURRENT' of 20 Aug.

See <http://debug.files.googlepages.com/Serial-20071022-004528.txt>

Below are some snippets:

db> show alllocks
Process 1406 (systat) thread 0xffffff002aa016a0 (100181)
shared sx allproc r = 0 (0xffffffff80a72820) locked _at_
/usr/src/sys/vm/vm_meter.c:130
exclusive sx sysctl lock r = 0 (0xffffffff80a72f40) locked _at_
/usr/src/sys/kern/kern_sysctl.c:1396
Process 1129 (rtorrent) thread 0xffffff000a6ae000 (100163)
exclusive sx user map r = 0 (0xffffff0001056890) locked _at_
/usr/src/sys/vm/vm_map.c:2195
Process 1105 (sshd) thread 0xffffff000a6ae350 (100162)
exclusive sx so_rcv_sx r = 0 (0xffffff000a78a928) locked _at_
/usr/src/sys/kern/uipc_sockbuf.c:145
Process 1040 (cron) thread 0xffffff0001c61350 (100130)
shared sx proctree r = 0 (0xffffffff80a72860) locked _at_
/usr/src/sys/kern/kern_fork.c:286
Process 998 (mysqld) thread 0xffffff002aa119f0 (100192)
exclusive sx so_rcv_sx r = 0 (0xffffff0003858670) locked _at_
/usr/src/sys/kern/uipc_sockbuf.c:145
Process 998 (mysqld) thread 0xffffff002aa12000 (100191)
exclusive sx so_rcv_sx r = 0 (0xffffff000abbb928) locked _at_
/usr/src/sys/kern/uipc_sockbuf.c:145
Process 932 (smbd) thread 0xffffff000140c000 (100068)
shared sx proctree r = 0 (0xffffffff80a72860) locked _at_
/usr/src/sys/kern/kern_fork.c:286


kernel config:

ident RUN-071021
include GENERIC
options         INCLUDE_CONFIG_FILE
nooption        SMP
nocpu           I486_CPU
nocpu           I586_CPU
nooption        SCHED_4BSD
options         SCHED_ULE
device          crypto
options         IPSEC
options         LIBALIAS
options         IPFIREWALL
options         IPFIREWALL_VERBOSE
options         IPFIREWALL_FORWARD
options         IPFIREWALL_NAT
options         GEOM_JOURNAL
options         KDB
options         DDB
options         KDB_TRACE
options         ALT_BREAK_TO_DEBUGGER
options         INVARIANTS
options         INVARIANT_SUPPORT
options         WITNESS
options         WITNESS_SKIPSPIN
nodevice        umass
device          ucom
device          uplcom


loader.conf:

vfs.root.mountfrom="zfs:base/system"
if_bridge_load="YES"
dummynet_load="YES"
ipdivert_load="YES"
zfs_load="YES"
accf_http_load="YES"


With an older kernel it once was just

db> show alllocks
Process 1130 (rtorrent) thread 0xffffff000962e9f0 (100160)
exclusive sx so_rcv_sx r = 0 (0xffffff000987e670) locked _at_
/usr/src/sys/kern/uipc_sockbuf.c:145
Process 1096 (sshd) thread 0xffffff000962a350 (100170)
exclusive sx so_rcv_sx r = 0 (0xffffff00096f9100) locked _at_
/usr/src/sys/kern/uipc_sockbuf.c:145
Process 996 (mysqld) thread 0xffffff0031e0c000 (100191)
exclusive sx so_rcv_sx r = 0 (0xffffff0009870be0) locked _at_
/usr/src/sys/kern/uipc_sockbuf.c:145

<http://debug.files.googlepages.com/Serial-20071021-020559.txt>


Please suggest any other commands to run in DDB if needed.
Cores are saved.

-- 
With best regards, Gleb Kozyrev.