"842" is a compression scheme and this is the software implementation
which is too slow to really use beyond a proof of concept. It can be
selected in ZRAM, ZSWAP, or `fs/pstore`, and is here for completeness.
In general you need a Power8 or better with 842-in-hardware for it to
be fast, but other 842-accelerators are emerging.
Signed-off-by: Tony Butler <spudz76@gmail.com>
a7f3a51982