Re: start_kernel / local_irq_enable() can be very slow

[Linus Torvalds <torvalds@osdl.org>]

On Sun, 13 Nov 2005, Andrew Morton wrote:
> 
> You could do something like:
> 
> int trace_irqs;
> 
> 	trace_irqs = 1;
> 	local_irq_enble();
> 	trace_irqs = 0;

Do "trace_irqs = 10" first.

> then, over in handle_IRQ_event():
> 
> 	if (trace_irqs)
> 		print_symbol("calling %s\n", (unsigned long)action->handler);

And decrement it here somewhere.

If it's delayed by up to three seconds, it sounds like there's a _lot_ of 
interrupts happening, and I don't think there's any point in showing all 
of them.

			Linus