[PATCH v4 7/8] lockdep: Change hardirq{s_enabled,_context} to per-cpu variables

[Peter Zijlstra]

On Tue, Jun 23, 2020 at 05:00:31PM +0200, Ahmed S. Darwish wrote:
> On Tue, Jun 23, 2020 at 10:36:52AM +0200, Peter Zijlstra wrote:
> ...
> > -#define lockdep_assert_irqs_disabled()	do {				\
> > -		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
> > -			  current->hardirqs_enabled,			\
> > -			  "IRQs not disabled as expected\n");		\
> > -	} while (0)
> > +#define lockdep_assert_irqs_enabled()					\
> > +do {									\
> > +	WARN_ON_ONCE(debug_locks && !this_cpu_read(hardirqs_enabled));	\
> > +} while (0)
> >
> 
> Can we add a small comment on top of lockdep_off(), stating that lockdep
> IRQ tracking will still be kept after a lockdep_off call?

That would only legitimize lockdep_off(). The only comment I want to put
on that is: "if you use this, you're doing it wrong'.