[$] Persistent memory for transient data

Arguably, the most notable characteristic of persistent memory is that itis persistent: it retains its contents over power cycles. One otherimportant aspect of these persistent-memory arrays that, we are told, willsoon be everywhere, is their sheer size and low cost; persistent memory isa relatively inexpensive way to attach large amounts of memory to a system. Large,cheap memory arrays seem likely to be attractive to users who may not careabout persistence and who can live with slower access speeds. Supportingsuch users is the objective of a pair of patch sets that have been circulating in recent months.