Re: Strange interrupt behaviour
Andi Kleen (ak@muc.de)
Sun, 12 Jul 1998 17:36:53 +0200
On Sun, Jul 12, 1998 at 05:26:03PM +0200, Alan Cox wrote:
> > Unfortunately the interrupt stack more or less requires the indirect
> > current scheme, because otherwise current could not be accessed inside
> > interrupt handlers (the interrupt entry routine would just copy current
> > to the bottom of the irq stack)
>
> "Current" is not meaningful in an interrupt handler anyway. In fact it
> would be nice to arrange that "current" faulted on an IRQ.
The problem is smp_processor_id(). It is one of the first functions
evaluated in the interrupt entry code, and it is - surprise, surprise -
defined as (current->processor). I have not checked whether there are
other interactions like this in e.g. the spinlock code too.
-Andi
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