Hey folks,
I'm trying to understand the schedule() code. I've got most of it
down, but a couple parts having to do with task_struct->activated and
task_struct->array are confusing me. What does activated stand for,
and what does array point to? At first guess it would seem like array
is the priority array that the task is on, but then this code makes no
sense:
if (!rt_task(next) && next->activated > 0) {
unsigned long long delta = now - next->timestamp;
if (next->activated == 1)
delta = delta * (ON_RUNQUEUE_WEIGHT * 128 / 100) / 128;
array = next->array;
dequeue_task(next, array);
recalc_task_prio(next, next->timestamp + delta);
enqueue_task(next, array);
}
why have array = next->array when we _just_ got next off an array we
already had the pointer to? Also, it seems like this is the code
where RR/FIFO scheduling is implemented. I say this only because this
is the only code past the point when a task is selected where
something is conditional on rt_task(next). OK, but what does
next->activated do here (and why are tasks with next->activated <= 0
treated as realtime?) OR am I wrong about this being the RR/FIFO code
and if so, where is it? Please help, I'm fairly lost :(
Thanks in advance,
Athul Acharya
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