On Tue, 21 Jul 98 13:03:38 METDST, Alessandro Muzzetta
<muzzetta@liotro.dipmat.unict.it> said:
> It seems that the counter for a SCHED_FIFO process is never
> reset. After the first time-slice, schedule() will be called
> on every clock tick.
> Can anyone confirm this? Is SCHED_FIFO supposed to work this
> way?
Whenever there are no runnable processes with non-zero counter, we share
out a bit more counter to _all_ processes using the assignment
p->counter = (p->counter >> 1) + p->priority;
Now, a SCHED_FIFO process had better not be compute bound, else our
system is in a permanent tight realtime loop! As long as the
recrediting gets run occassionally, and the SCHED_FIFO never spins in a
tight loop for too long, we won't get this problem. If SCHED_FIFO
_does_ spin for longer than p->counter, then yes, we'll be rescheduling
every clock tick.
--Stephen
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