Hans Reiser writes: > Horst von Brand wrote: > > > > > > >Funny that the "texbook algorithms" aren't used in real life. Wonder why... > > > > > Try BSD. If the BSD book can be believed, they use"texbook algorithms".
The "textbook" one-way elevator (as indeed exemplified by FreeBSD's
src/sys/kern/subr_disk.c:bioq_disksort()) has well-known weaknesses. For
example,
dd if=/dev/zero of=FILE
can easily monopolize device queue and starve accesses to the blocks
with low block numbers.
>
> ;-)
Nikita.
