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SubjectRe: An elevator algorithm
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Jens Axboe <axboe@suse.de> writes:

> > modification Peter suggested there can be more and we should track the one
> > more on the back of the queue. I don't think it's worthwhile.
>
> Agree, I don't think the added complexity would be worth it.

So that leaves two choices:

1. Perfect elevator (CSCAN) without the O(1) optimization. (My second
patch.)
2. Suboptimal elevator with the O(1) optimization. (Andrea's suggested
modification to my second patch.)

Since the request queue can not be very long, minimizing disk head
movements ought to be more important than saving a few CPU cycles, so
I vote for the first alternative.

--
Peter Österlund Email: peter.osterlund@mailbox.swipnet.se
Sköndalsvägen 35 f90-pos@nada.kth.se
S-128 66 Sköndal Home page: http://home1.swipnet.se/~w-15919
Sweden Phone: +46 8 942647

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