[dm-devel] Re: Do we support ioprio on SSDs with NCQ (Was: Re: IO scheduler based IO controller V10)

[Jens Axboe <jens axboe oracle com>]

On Mon, Oct 05 2009, Corrado Zoccolo wrote:
> On Mon, Oct 5, 2009 at 5:06 PM, Jeff Moyer <jmoyer redhat com> wrote:
> > Corrado Zoccolo <czoccolo gmail com> writes:
> >
> >> Moreover, I suggest removing also the slice_resid part, since its
> >> semantics doesn't seem consistent.
> >> When computed, it is not the residency, but the remaining time slice.
> >
> > It stands for residual, not residency.  Make more sense?
> It makes sense when computed, but not when used in rb_key computation.
> Why should we postpone queues that where preempted, instead of giving
> them a boost?

We should not, if it is/was working correctly, it should allow both for
increase/descrease of tree position (hence it's a long and can go
negative) to account for both over and under time.

-- 
Jens Axboe