Re: [PATCH v2 1/3] locking: Document the semantics of spin_is_locked()

From: Andrea Parri
Date: Tue Apr 03 2018 - 10:07:30 EST


On Tue, Apr 03, 2018 at 02:52:33PM +0100, David Howells wrote:
> Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > > It's more complicated than that. This function is dangerous and should be
> > > used with extreme care. In the case where CONFIG_SMP=n the value is locked
> > > one way or the other and it might be the wrong way.
> >
> > You mean "unlocked"? (aka, return 0)
>
> No, I mean "fixed", sorry. We've had problems stemming from this before on UP
> systems.

Sorry, but I don't understand your objection: are you suggesting to add
something like "Always return 0 on !SMP" to the comment? what else?

Andrea


>
> David