panic: kmem_malloc(171642880): kmem_map too small: 31387648 total allocated

I got this panic when trying to make -j4 buildworld.

If this is relevant: My userland is some weeks old, I just had time to
upgrade kernel yesterday (because of the ieee802.11 insecurity) and wanted
to update the rest of the world today:

dmesg can be found here:
http://stud4.tuwien.ac.at/~e0125637/fbsd/dmesg

backtrace:
[GDB will not be able to debug user-mode threads: /usr/lib/libthread_db.so: Undefined symbol "ps_pglobal_lookup"]
GNU gdb 6.1.1 [FreeBSD]
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This GDB was configured as "i386-marcel-freebsd".

Unread portion of the kernel message buffer:
panic: kmem_malloc(171642880): kmem_map too small: 31387648 total allocated
cpuid = 0
KDB: enter: panic
Dumping 478 MB (2 chunks)
  chunk 0: 1MB (159 pages) ... ok
  chunk 1: 478MB (122336 pages) 462 446 430 414 398 382 366 350 334 318 302 286 270 254 238 222 206 190 174 158 142 126 110 94 78 62 46 30 14

#0  doadump () at pcpu.h:166
166		__asm __volatile("movl %%fs:0,%0" : "=r" (td));
(kgdb) bt
#0  doadump () at pcpu.h:166
#1  0xc044e186 in db_fncall (dummy1=0, dummy2=0, dummy3=1999, 
    dummy4=0xd337e89c " \024}À") at /usr/src/sys/ddb/db_command.c:489
#2  0xc044df02 in db_command (last_cmdp=0xc07d0b24, cmd_table=0x0, 
    aux_cmd_tablep=0xc0797874, aux_cmd_tablep_end=0xc0797878)
    at /usr/src/sys/ddb/db_command.c:404
#3  0xc044e015 in db_command_loop () at /usr/src/sys/ddb/db_command.c:455
#4  0xc0450275 in db_trap (type=3, code=0) at /usr/src/sys/ddb/db_main.c:221
#5  0xc05726ae in kdb_trap (type=0, code=0, tf=0xd337ea50)
    at /usr/src/sys/kern/subr_kdb.c:485
#6  0xc073acba in trap (frame=
      {tf_fs = 8, tf_es = 40, tf_ds = -751370200, tf_edi = 256, tf_esi = 1, tf_ebp = -751310184, tf_isp = -751310212, tf_ebx = -751310120, tf_edx = 0, tf_ecx = -1056755712, tf_eax = 18, tf_trapno = 3, tf_err = 0, tf_eip = -1068031216, tf_cs = 32, tf_eflags = 646, tf_esp = -1065898234, tf_ss = -1065904983})
    at /usr/src/sys/i386/i386/trap.c:614
#7  0xc072349a in calltrap () at /usr/src/sys/i386/i386/exception.s:137
#8  0xc0572310 in kdb_enter (msg=0x12 <Address 0x12 out of bounds>)
    at cpufunc.h:60
#9  0xc054f77e in panic (
    fmt=0xc078b904 "kmem_malloc(%ld): kmem_map too small: %ld total allocated")
    at /usr/src/sys/kern/kern_shutdown.c:539
#10 0xc06e777b in kmem_malloc (map=0xc10690a8, size=171642880, flags=2)
    at /usr/src/sys/vm/vm_kern.c:299
#11 0xc06dc597 in page_alloc (zone=0x0, bytes=18, 
    pflag=0x12 <Address 0x12 out of bounds>, wait=18)
    at /usr/src/sys/vm/uma_core.c:956
#12 0xc06df292 in uma_large_malloc (size=171642880, wait=2)
    at /usr/src/sys/vm/uma_core.c:2698
#13 0xc0541aee in malloc (size=171642880, mtp=0xc07a9020, flags=2)
    at /usr/src/sys/kern/kern_malloc.c:322
#14 0xc0505770 in g_read_data (cp=0x12, offset=Unhandled dwarf expression opcode 0x93
) at geom.h:290
#15 0xc07199a8 in g_bsd_try (gp=0xc4240780, gsp=0xc359fbc0, cp=0x12, 
    secsize=18, ms=0xc31b8c00, offset=171639120)
    at /usr/src/sys/geom/geom_bsd.c:209
#16 0xc071a5a5 in g_bsd_taste (mp=0xc4240780, pp=0xa3b0150, flags=0)
    at /usr/src/sys/geom/geom_bsd.c:538
#17 0xc050777a in g_new_provider_event (arg=0xc399c880, flag=0)
    at /usr/src/sys/geom/geom_subr.c:459
#18 0xc050239c in one_event () at /usr/src/sys/geom/geom_event.c:206
#19 0xc05024b5 in g_run_events () at /usr/src/sys/geom/geom_event.c:226
#20 0xc0505b65 in g_event_procbody () at /usr/src/sys/geom/geom_kern.c:141
#21 0xc0532aa0 in fork_exit (callout=0xc0505ab0 <g_event_procbody>, arg=0x12, 
    frame=0x12) at /usr/src/sys/kern/kern_fork.c:790
#22 0xc07234fc in fork_trampoline () at /usr/src/sys/i386/i386/exception.s:198
(kgdb)