Re: CFQ will be the new default IO scheduler - why?

[Al Boldi <a1426z@gawab.com>]

Justin Piszcz wrote:
> On Mon, 24 Jul 2006, Matthias Andree wrote:
> > On Sun, 23 Jul 2006, Paa Paa wrote:
> >> The default IO scheduler in 2.6.18 will be CFQ (Complete Fair Queuing)
> >> instead of AS (Anticipatory Scheduler) as described here:
> >> http://wiki.kernelnewbies.org/Linux_2_6_18. I tried to find (here, at
> >> lkml) the discussion about this change with no luck.
> >
> > That wiki document nicely shows the advantage of the scheduler, namely
> > that you have "ionice", which isn't possible for AS or Deadline
> > Schedulers - this allows the operating system to run processes like
> > updatedb with "nice I/O", meaning these hold when you're doing other
> > I/O.
>
> Should there be a default scheduler per filesystem?  As some filesystems
> may perform better/worse with one over another?

It's currently perDevice, and should probably be extended to perMount.

Thanks!

--
Al