Messages in this thread |  | | Date | Tue, 3 Apr 2018 15:35:43 +0200 | From | Andrea Parri <> | Subject | Re: [PATCH v2 1/3] locking: Document the semantics of spin_is_locked() |
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On Tue, Apr 03, 2018 at 01:49:09PM +0100, David Howells wrote: > Andrea Parri <andrea.parri@amarulasolutions.com> wrote: > > > +/** > > + * spin_is_locked() - Check whether a spinlock is locked. > > + * @lock: Pointer to the spinlock. > > + * > > + * This function is NOT required to provide any memory ordering > > + * guarantees; it could be used for debugging purposes or, when > > + * additional synchronization is needed, accompanied with other > > + * constructs (memory barriers) enforcing the synchronization. > > + * > > + * Return: 1, if @lock is (found to be) locked; 0, otherwise. > > 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)
Andrea
> > David
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