Re: elevator algorithm bug in ll_rw_blk.c

Chip Salzenberg (chip@perlsupport.com)
Fri, 13 Nov 1998 11:59:24 -0500

According to Stephen C. Tweedie:
> The queue is always kept sorted, yes, but as soon as an IO starts,
> the current request is not removed from the queue until IO is
> complete (except for SCSI, which does its own queue ordering). Once
> 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?

-- 
Chip Salzenberg        - a.k.a. -        <chip@perlsupport.com>
      "There -- we made them swerve slightly!"   //MST3K


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