Re: [PATCH] cfq + io priorities

[Pavel Machek <pavel@suse.cz>]

Hi!

> > At least idle class can not be used to hold important semaphore
> > forever (even low-priority prosses receive enough time not to hold
> > important semaphores too long)... I believe you should do the same (==
> > get rid of idle class for now, and clearly state that realtime ones
> > are not _guaranteed_ anything).
> 
> That's not doing something about it, that's giving up... 

:-) Yes. That's what we do for scheduler, already. [And its better to
give up than to have DoS security hole, right?]

> You could allow idle prio to proceed, if it holds a resource that could
> potentially block others.

I guess you can't push this for 2.6. And notice that we use same
solution for cpu scheduler, where solution is quite easy (with no
hot-paths overhead).
							Pavel
-- 
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]