Design alternative: No buffer cache (a variation tried out in
Mach). In a buffer cache system, the number of buffer cache entries
and amount of memory used for buffer caches are decided at
configuration or during boot up, so the amount of memory allocated for
buffers and the amount allocated for processes' memory is not as
adaptive.
bufhash; LOCKED, LRU, AGE, and EMPTY lists. how buffers are
moved among these lists. bufhash and buffer headers no longer
use/contain the disk address. why was this design choice made? what
are the implications?