I was getting these messages as well.  I looked into the problem and
found that in /usr/src/sys/vm/vm_map.h, if I increased VM_MAPENT from 500
to 1000, the messages go away.  Depending on the use of your system, you
may need to increase this number even more, but don't gratuitously increase
it "for safety", because it eats into the amount of user memory available
to your users' processes.
-Brian

On Feb 10,  6:36pm, Olaf Seibert wrote:
} Subject: panic: vm_map_entry_create: out of map entries
} On a client's system, that I recently installed with 1.3, I got the
} report that it had crashed with this panic: vm_map_entry_create: out of
} map entries.
} 
} Looking at options(4) I tried to increase NKMEMCLUSTERS. Although it
} mentions a panic where it might be useful to do so, and that panic
} differs from mine, it does not seem to exist. So maybe the text changed or
} something.
} 
} Is increasing NKMEMCLUSTERS a sensible idea to do? If not, what else?
} 
} Oh, btw, it saved a crash dump, but I forgot the incantation to get
} gdb to read it. Can anybody tell me?
} 
} dmesg output follows:
} 
} Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.  All rights reserved.
} Copyright (c) 1982, 1986, 1989, 1991, 1993
}     The Regents of the University of California.  All rights reserved.
} 
} NetBSD 1.3 (xxxxx) #2: Tue Feb 10 03:45:26 CET 1998
}     xxxxxxxxxxxxxxx:/usr/src/sys/arch/i386/compile/xxxxxxxx
} 
} cpu0: family 5 model 4 step 3
} cpu0: Intel Pentium/MMX (586-class)
} real mem  = 33157120
} avail mem = 31137792
} using 430 buffers containing 1761280 bytes of memory
} mainbus0 (root)
} pci0 at mainbus0 bus 0: configuration mode 1
} pchb0 at pci0 dev 0 function 0
} pchb0: vendor 0x8086 product 0x7100 (rev. 0x01)
} pcib0 at pci0 dev 7 function 0
} pcib0: vendor 0x8086 product 0x7110 (rev. 0x01)
} vendor 0x8086 product 0x7111 (IDE mass storage, interface 0x80, revision 0x01) at pci0 dev 7 function 1 not configured
} vendor 0x8086 product 0x7112 (USB serial bus, revision 0x01) at pci0 dev 7 function 2 not configured
} vendor 0x8086 product 0x7113 (miscellaneous bridge, revision 0x01) at pci0 dev 7 function 3 not configured
} vendor 0x5333 product 0x8901 (VGA display, revision 0x04) at pci0 dev 11 function 0 not configured
} isa0 at pcib0
} ne1 at isa0 port 0x300-0x31f irq 10
} ne1: NE2000 Ethernet
} ne1: Ethernet address xxxxxxxxxxxxxxxxx
} com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
} com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
} lpt0 at isa0 port 0x378-0x37b irq 7
} wdc0 at isa0 port 0x1f0-0x1f7 irq 14
} atapibus0 at wdc0
} wd0 at wdc0 drive 0: <QUANTUM FIREBALL ST3.2A>
} wd0: 3079MB, 6256 cyl, 16 head, 63 sec, 512 bytes/sec
} wd0: using 16-sector 16-bit pio transfers, lba addressing
} npx0 at isa0 port 0xf0-0xff: using exception 16
} vt0 at isa0 port 0x60-0x6f irq 1
} vt0: unknown s3, 80 col, color, 6 scr, mf2-kbd, [R3.32]
} vt0: console
} fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
} fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
} biomask 4040 netmask 4440 ttymask 44c2
} boot device: wd0
} root on wd0a dumps on wd0b
} root file system type: ffs
} 
} -Olaf.
} --
} ___ Olaf 'Rhialto' Seibert      D787B44DFC896063 4CBB95A5BD1DAA96 
} \X/ It's not easy having a good time    rhialto@polder.ubc.kun.nl
>-- End of excerpt from Olaf Seibert