Make amaps use less kernel memory (2nd try)

The original diff would crash at least i386 and powerpc, as spotted by
guenther@ The reason was an incorrect use of sizeof in amap_lookups().

Confirmation that powerpc works by mpi@ and mglocker@

"throw it in" deraadt@

Original commit message:

This is achieved by grouping amap slots into chunks that are allocated
on-demand by pool(9). Endless "fltamapcopy" loops because of kmem
shortage should be solved now. The kmem savings are also important to later
enable vmm(4) to use larged shared memory mappings for guest VM RAM.

This adapts libkvm also because the amap structure layout has changed.

Testing and fix of libkvm glitch in initial diff by tb@
Feedback and "time to get this in" kettenis@

0 files changed, 0 insertions, 0 deletions