Re: [PATCH 1/4] Blackfin: arch patch for 2.6.18

From: Arnd Bergmann
Date: Tue Sep 26 2006 - 05:44:36 EST


On Tuesday 26 September 2006 05:42, Aubrey wrote:
> So, in the kernel space, there is always one bit in the IPEND register
> is set. And if there comes a timer interrupt event, in the timer
> interrupt handler, there should be two bits set in the IPEND register.
> Therefore, schedule happens in the return_from_int.
>
> So, I still say there is no latency here.
>

Well, if that's true, you should change your idle function not to
explicitly call schedule().

I haven't really understood how you preempt the idle task, but
I guess you can simplify the standard

| while (1) {
| while (!need_resched())
| asm("idle");
| schedule();
| }

to

| while (1)
| asm("idle");


Arnd <><
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