Random panics

Hi

I get these panics at what appears random intervals and indeterminate
cause.  Higher load does seem to increase the frequency though.  On
an unload machine  it might occur this often:

-rw-------   1 root  wheel  201261056 Feb  3 23:26 vmcore.37
-rw-------   1 root  wheel  201261056 Feb  4 17:57 vmcore.38
-rw-------   1 root  wheel  201261056 Feb  4 21:22 vmcore.39
-rw-------   1 root  wheel  201261056 Feb  4 23:26 vmcore.40
-rw-------   1 root  wheel  201261056 Feb  5 07:56 vmcore.41

although that's how much space I have for vmcores, so it might have
missed a few recently.

Panic messages and backtrace below.  I've preserved the kernel, so
I can poke around as requested.

Ian


panic: page fault
panic messages:
---
Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x24
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc0512ede
stack pointer           = 0x10:0xcdb1aab0
frame pointer           = 0x10:0xcdb1aad0
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = resume, IOPL = 0
current process         = 29 (swi1: net)
trap number             = 12
panic: page fault
at line 819 in file ../../../i386/i386/trap.c
Stack backtrace:
backtrace(c0657fc1,c06a4080,333,c066963e,100) at backtrace+0x17
__panic(c066963e,333,c06481cf,c0669496,1) at __panic+0xd4
trap_fatal(cdb1aa70,24,10430,c3dbc13c,24) at trap_fatal+0x346
trap(10018,c3db0010,10,0,c0fc02a0) at trap+0x123
calltrap() at calltrap+0x5
--- trap 0xc, eip = 0xc0512ede, esp = 0xcdb1aab0, ebp = 0xcdb1aad0 ---
propagate_priority(c0fc02a0,c3cd8e70,2,0,c06a57a0) at propagate_priority+0x7e
turnstile_wait(0,c06a848c,c3cd8e70,0,0) at turnstile_wait+0x2f4
_mtx_lock_sleep(c06a848c,0,0,0,1900) at _mtx_lock_sleep+0xd8
tcp_input(c0fd4900,14,83,c05017d5,c0fc02a0) at tcp_input+0x31e
ip_input(c0fd4900,2b6b88d2,c06ac8b4,0,c06a7818) at ip_input+0xa8c
netisr_processqueue(c06a7818,5bc0ce80,2955e745,0,c0fb5840) at netisr_processqueu
e+0xd9
swi_net(0,42fcc,46a54,425ec,c0fc02a0) at swi_net+0xc9
ithread_loop(c0fbd480,cdb1ad48,c5a0,43740,0) at ithread_loop+0x1d8
fork_exit(c04d46a0,c0fbd480,cdb1ad48) at fork_exit+0x80
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xcdb1ad7c, ebp = 0 ---

syncing disks, buffers remaining... 1819 1819 kernel trap 12 with interrupts dis
abled


Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x24
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc0512ede
stack pointer           = 0x10:0xcdb14c08
frame pointer           = 0x10:0xcdb14c28
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = resume, IOPL = 0
current process         = 27 (swi8: tty:sio clock)
trap number             = 12
panic: page fault
at line 819 in file ../../../i386/i386/trap.cUptime: 8h28m27s
Dumping 191 MB
 16 32 48 64 80 96 112 128 144 160 176
---
(kgdb) bt
#0  doadump () at ../../../kern/kern_shutdown.c:240
#1  0xc04eaa39 in boot (howto=260) at ../../../kern/kern_shutdown.c:374
#2  0xc04eae38 in __panic () at ../../../kern/kern_shutdown.c:552
#3  0xc061cd56 in trap_fatal (frame=0xcdb14bc8, eva=0)
    at ../../../i386/i386/trap.c:819
#4  0xc061c373 in trap (frame=
      {tf_fs = 553648152, tf_es = -1012269040, tf_ds = 16, tf_edi = 0, tf_esi = -1057226752, tf_ebp = -844018648, tf_isp = -844018700, tf_ebx = -1009938832, tf_edx = -1066761076, tf_ecx = -1057226752, tf_eax = 36, tf_trapno = 12, tf_err = 0, tf_eip = -1068421410, tf_cs = 8, tf_eflags = 65683, tf_esp = -1011813392, tf_ss = -1057200128}) at ../../../i386/i386/trap.c:250
#5  0xc0512ede in propagate_priority (td=0xc3cd8e70)
    at ../../../kern/subr_turnstile.c:230
#6  0xc0513764 in turnstile_wait (ts=0xc0fb4340, lock=0xc06a848c, owner=0x0)
    at ../../../kern/subr_turnstile.c:510
#7  0xc04e0148 in _mtx_lock_sleep (m=0xc06a848c, opts=0, file=0x0, line=0)
    at ../../../kern/kern_mutex.c:536
#8  0xc058d198 in tcp_slowtimo () at ../../../netinet/tcp_timer.c:141
#9  0xc0528de9 in pfslowtimo (arg=0x0) at ../../../kern/uipc_domain.c:242
#10 0xc04fcf7e in softclock (dummy=0x0) at ../../../kern/kern_timeout.c:226
#11 0xc04d4878 in ithread_loop (arg=0xc0fbd580)
    at ../../../kern/kern_intr.c:547
#12 0xc04d34e0 in fork_exit (callout=0xc04d46a0 <ithread_loop>, arg=0x0, 
    frame=0x0) at ../../../kern/kern_fork.c:799