(no subject)

Alan Cox (alan@lxorguk.ukuu.org.uk)
Wed, 9 May 2001 15:10:31 +0100 (BST)


> while(!!time_before(jiffies, timer))
> {
> if(!!(*event & mask))
> {
> stat = 0;
> break;
> }
> schedule();

You want to yield as well otherwise you may just spin anyway

> Both of these procedures schedule() while waiting for something to
> happen. The wait can be very long (1 second) so I don't want to
> just spin eating CPU cycles. I have to give the CPU to somebody.

So use a timer

void tick_tick_boom(unsigned long l)
{
struct my_device *d = (struct my_device *)l;

if(its_still_busy(d))
{
d->timer_count--;
if(d->timer_count)
{
/* Try again until timer_count hits zero */
add_timer(&t->timer, jiffies+1);
return;
}
else
{
/* Lose some .. */
d->event_status = TIMEOUT;
}
}
else
{
/* Win some .. */
d->event_status = OK;
}
/* Wake up the invoker */
wake_up(&d->timer_wait);
}

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