Messages in this thread |  | | Date | Tue, 3 Apr 2018 07:17:18 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH v2 1/3] locking: Document the semantics of spin_is_locked() |
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On Tue, Apr 03, 2018 at 02:52:33PM +0100, David Howells wrote: > Andrea Parri <andrea.parri@amarulasolutions.com> 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.
Oooh... I had forgotten about spinlocks disappearing on UP systems, good catch!
Suggestions for a fix? Clearly great care is required when using it in things like WARN_ON()...
Thanx, Paul
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