[coyotos-dev] Usermode interrupt handling delayed until end of quanta?

[Jonathan S. Shapiro]

Jeroen:

So the more I thought about this, the more it worried me. If we assume
that your patch is NOT applied, here is what ought to be happening:

 1. Interrupt goes off. IrqWait process is moved to the ready queue.
 2. Assuming nothing is busy waiting, you would reasonably expect the
    IrqWait process to run fairly soon, even with pure round-robin.

The current tick clock is set at 5ms (200/sec), so that's almost
certainly not the problem.

At present, the tick clock interval is also the quanta, so *that's* not
the problem.

What I suspect is that something in your code is busy-waiting, perhaps
because there currently no interval timer support. If that is not what
is going on, I would very much like to track this down. Can we somehow
work together to do that?


shap