Re: RFC for a new Scheduling policy/class in the Linux-kernel

Chris Friesen
2009-07-14T18:24:37Z

Raistlin wrote:

> Remember that all my points are concerned with budgets, i.e., a scenario
> where you have some mean to limit the capability of a task to ask for
> CPU time over some kind of period.
> And here it is where the problem comes since running C instead of having
> A busy waiting means:
> - that A is actually blocked, as said before;

Why does it make any difference that A is blocked rather than busy
waiting? In either case A cannot make forward progress.

> - that A's budget is not diminished.

If we're running B with A's priority, presumably it will get some amount
of cpu time above and beyond what it would normally have gotten during a
particular scheduling interval. Perhaps it would make sense to charge B
what it would normally have gotten, and charge the excess amount to A?

Chris