Re: elevator algorithm bug in ll_rw_blk.c
Alan Cox (alan@lxorguk.ukuu.org.uk)
Sun, 15 Nov 1998 17:40:52 +0000 (GMT)
> > that single IO request is complete, the driver then moves on to the
> > *next* request in the queue. It doesn't start again at the
> > beginning. So, we do correctly service the higher numbered requests
> > before going back to the low ones.
>
> But that's a *one-way* elevator. Ideal elevators are two-way, aren't they?
If you go for the shortest movement alone you starve the edges of the disks.
If you watch a real elevator you'll see they too use the elevator algorithm
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