1 Dec
2003
1 Dec
'03
4:41 a.m.
On Sunday 30 November 2003 05.03, Jack O'Quin wrote:
I don't see why this is a problem. All this has to happen for every
cycle, anyway. What difference does it make? And, why do you think we
don't understand this?
Sorry, I got my wording wrong! ("you" = developers in general)
But it is still a way to see that no client burns cycles where it should not -
jackd would not start (or stop). And you _can_ get fewer context switches,
but only if some client burns extra cycles.
Compare:
With jackd as highest priority:
* Client A running
* Jackd starts (higher prio than A), telling client B to run
* Jackd waits
* Client A contiues to run (higher prio than B)
- this could be something very short like preparing to go
to sleep after passing the baton.
* Client A done, goes to sleep.
* Client B runs - but later than expected...
* Client B done
* Jackd continues
Context switches: A->jd->A->B->jd
With jackd as lowest priority:
* Client A runs
* Jackd wants to start but has to wait
* Client A continues to run
* Client A done, goes to sleep
* Jackd starts, telling client B to run
* Client B starts
* Client B done
* Jackd continues, waits - B is finished
Context switches: A->jd->B->jd
Trying with jackd with lowest priority would atleast give you another
data point.
/RogerL
--
Roger Larsson
Skellefteå
Sweden
Roger Larsson <roger.larsson(a)norran.net>
writes:
No. It's rather difficult to prove. There's no "smoking gun".
But, I have no reason to believe that it works correctly, and I
suspect that it probably does not.
Is there a tread documenting your problems?
Anything else?
That's right. But, Paul and I have been working closely with this and
don't have much faith in the correctness of the 2.4 scheduler.
Have you told kernel developers about this?
This can be rather critical in embedded systems. What
problem does this solve?
It will better match what you think you do.
When jackd writes in the FIFO - expect client to start.
Jackd waits for baton - wait for client to finish.
But with jackd as highest priority:
Jackd writes to FIFO - nothing will happen for client.
Jackd _waits_ for baton - now client start, processes, finishes.