Re: [patch] cfq: ioprio inherit rt class

[Con Kolivas <kernel@kolivas.org>]

On Sunday 04 June 2006 03:40, Lee Revell wrote:
> On Sat, 2006-06-03 at 10:10 +1000, Con Kolivas wrote:
> > On Saturday 03 June 2006 03:12, Jens Axboe wrote:
> > > Not sure. RT io needs to be considered carefully, but I guess so does
> > > RT CPU scheduling. For now I'd prefer to play it a little safer, and
> > > only inheric the priority value and not the class.
> >
> > The problem I envisioned with that was that realtime tasks, if they don't
> > specify an io priority (as most current code doesn't), would basically
> > get io priority 4 and have the same proportion as any nice 0 SCHED_NORMAL
> > task whereas -nice tasks automatically are getting better io priority.
> > How about givent them normal class but best priority so they are at least
> > getting the same as nice -20?
>
> Con,
>
> Have you seen RT threads trying to disk IO 'in the wild' or is this a
> theoretical concern?  I don't know of any such apps.
>

Yeah, cd burning software comes to mind.

-- 
-ck