Re: Position paper

[Neal H. Walfield]

At Wed, 10 Jan 2007 18:50:37 +0100,
Tom Bachmann wrote:
> Neal H. Walfield schrieb:
> >> However, it is not clear to me how the policies creatable in this way
> >> can be ordered (e.g., can a pool of the first type exemplfied created as
> >> a subpool of the second example?).
> > 
> > Does my first example (with Alice and Bob) clarify this point?
> > 
> 
> To some extent. I'll try to give an example of the case I consider unclear:
> Suppose Bob and an unspecified number of other users all have allocated
> from the user pool (a proportional share pool). Now Bob wants to run an
> audio player. For this player, real-time guarantees about the scheduling
> are preferable, e.g. "run at least 2 ms every 20ms".
> Here it is not clear if Bob can derive such a pool from his main pool.

Bob might have his applications running under proportional share and
have set the audio player to a relatively high priority.

The application requests the schedule which the resource manager
considers in light of the current policy configuration.  When it is
not longer possible to meet the requested schedule, the resource
manager will send the application a fault when it is next scheduled to
run.

> >> What other policies exist? How are they ordered?
> > 
> > What do you mean by ordered?
> > 
> 
> The same thing which I described in terms of a music player above, but
> this time about memory.

Applications request memory.  As the schedule changes according to the
policy configuration, pages are evicted from applications which exceed
their allocation.