I've come to the conclusion that dma in 1.5R is just too unstable for the
Magnum to be usable with local disk.  I'm playing with 1.5 release + my
patches, and I've just turned up an interesting panic when trying to mount
an msdos filesystem...

panic: malloc: out of space in kmem_map                                         
Stopped in mount_msdos at       0x802d194c:     jr      ra                      
                bdslot: 0x802d1950:     nop                                     
db> 

Why on earth would kmem_map run out of space every time when mounting an
msdos filesystem?  Mounting ffs filesystems doesn't seem to pose any problems
so far.  1.5R didn't seem to have any problem mounting the very same msdos
filesystem.  Anyone have any suggestions?

-Mark