kernel IO schedulers

[Collins Richey]

On Fri, 31 Dec 2004 16:25:11 -0800, Net Llama! <netllama at linux-sxs.org> wrote:
> On 12/31/2004 10:34 AM, Jerry McBride wrote:
> >  On Thursday 30 December 2004 14:58, Net Llama! wrote:
> >  > I could be wrong, but I think that in 2.6.10 there's a choice of several
> >  > different schedulers in the kernel:
> >  >
> >  > # IO Schedulers
> >  > #
> >  > CONFIG_IOSCHED_NOOP=y
> >  > CONFIG_IOSCHED_AS=y
> >  > CONFIG_IOSCHED_DEADLINE=y
> >  > CONFIG_IOSCHED_CFQ=y
> >  >
> >  > What I'm wondering is what happens if you chose Y for all of them (as
> >  > above)?
> >  >
> >  > The reason I'm asking is that I did choose Y for all of them, and now in
> >  > 2.6.10 (but not in earlier kernels) i'm getting some horrific
> >  > performance in X (XFCE specifically).  Scrolling in windows is sluggish,
> >  > sometimes even typing gets lagged.  I'm starting to think that I was
> >  > supposed to choose just one of the schedulers, but I'd like some input.
> >
> > Clicking yes, makes them available in the kernel. At boot time, make your
> > scheduler choice as a kernel parameter like:
> >
> >  elevator= [IOSCHED]
> >    Format: {"as"|"cfq"|"deadline"|"noop"}
> >    See Documentation/block/as-iosched.txt
> >    and Documentation/block/deadline-iosched.txt for details.
> >
> > The default scheduler is deadline.
> 
> OK, thanks.  So i'm using the anticipatory scheduler, which is what I
> thought i was using for previous 2.6.x kernels.  However, performance is
> very noticably not the same (nor as good) as it was for previous 2.6.x
> kernels.
> 
> What is everyone else using right now?
> 

This is interesting. I find that I have the same config parameters as
you, and yes, the kernel picks anticipatory scheduling,. I haven't
moved to 2.6.10 yet, so I'll have to pay attention when I do.

-- 
 Collins