How to resize swap in NetBSD 10?

[Tom Lane <tgl%sss.pgh.pa.us@localhost>]

I have a macppc machine running NetBSD 10.1 that has been failing to
run some larger programs.  dmesg showed things like

[ 1750816.967766] trap: pid 18392.18392 (perl): user write DSI trap @ 0xbc949000 by 0xfdc9ea88 (DSISR 0x42000000, err=12)
[ 1750816.967766] UVM: pid 18392.18392 (perl), uid 1001 killed: out of swap

So I figured I'd better enlarge the swap partition from its 512MB
size.  I deleted the swap and root partitions, remade them with the
desired sizes, and reinstalled netbsd into the root.  That all seems
to have gone according to plan, and the partition sizes are right
according to pdisk:

$ sudo pdisk /dev/wd0c
Edit /dev/wd0c -
Command (? for help): p

Partition map (with 512 byte blocks) on '/dev/wd0c'
 #:                type name      length   base      ( size )
 1: Apple_partition_map Apple         63 @ 1        
 2:           Apple_HFS boot       20480 @ 64        ( 10.0M)
 3:     Apple_UNIX_SVR2 swap     4194304 @ 20544     (  2.0G) S1  SFS k0  (swap)
 4:     Apple_UNIX_SVR2 root   112995392 @ 4214848   ( 53.9G) S0 RUFS k0  /

Device block size=512, Number of Blocks=117210240 (55.9G)
DeviceType=0x0, DeviceId=0x0

But I was sad to find I still have only 512MB of swap space:

$ swapctl -l -h
Device      Size     Used    Avail Capacity  Priority
/dev/wd0b   512M       0B     512M     0%    0

I guess I need to do something to enlarge the swap space,
but googling only yielded suggestions to use "mkswap"
which doesn't exist on this system.

If anyone can point me in the right direction, it'd be
much appreciated.

			regards, tom lane