Re: [PATCH] local_irq_disable removal

Ingo Molnar
2005-06-13T09:17:04Z

* Esben Nielsen <simlo@phys.au.dk> wrote:

> I will also try to make a lock which introduces the "notion of
> locallity" (i.e. have the same semantics as a normal spin_lock/mutex)
> into the code, but in !PREEMPT_RT will turn out to be just
> local_irq_disable() or preempt_disable(). A lot of the
> local_irq_disable() should be replaced with that.

yes, this would be the right approach. Note that we already do something
like that in the per_cpu_locked API, we hide a spinlock there, which
gets turned off for !PREEMPT_RT. For local_irq_disable() replacements
we'd need a separate API.

(one thing to watch out for are smp_call_function() handlers. These
still execute in hardirq context even on PREEMPT_RT. E.g. in buffer.c
you'll see such code.)

Ingo