On Tue, Jul 31, 2012 at 02:06:41PM -0400, Steven Rostedt wrote:
> On Tue, 2012-07-31 at 10:44 -0700, Paul E. McKenney wrote:
>
> > OK, I interpret this as excluding NMI handlers, but please let me
> > know if I am still being naive. ;-)
> >
>
> You are correct. This is only called where lockdep is called (to trace
> enabling of IRQS). Note, that its called before normal irqs are actually
> enabled (interrupts are still disabled), this is why it's called outside
> of the in_irq() sections, because it is called just before returning
> back to process context.
>
> That said, because NMIs are so difficult, lockdep doesn't record the
> disabling (and then enabling) of interrupts when an NMI triggers. Thus,
> the irqsoff tracer also does not record NMIs. Which is fine, because
> NMIs should not take long to run (we can add other mechanisms to time
> NMI length if that is needed), and NMIs should not be enabling
> interrupts nor taking any locks.
>
> >From arch/x86/kernel/entry_64.S:
>
> /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */
Then the patch on my earlier email should do it for you.
Thanx, Paul
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