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Subject: Re: spin_is_locked() broken for uniprocessor?
From: Peter Zijlstra <peterz@infradead.org>
To: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
       Kumar Gala <galak@kernel.crashing.org>,
       Linux-Kernel List <linux-kernel@vger.kernel.org>,
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Date: Wed, 19 Aug 2009 11:41:10 +0200
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On Wed, 2009-08-19 at 10:38 +0100, David Howells wrote:
> Thomas Gleixner <tglx@linutronix.de> wrote:
> 
> > > which implies to me that spin_is_locked() will always return false.  Is this
> > > expected behavior.
> > 
> > That's wrong. spin_is_locked should always return true on UP.
> 
> Surely it's not that simple?  Maybe spin_is_lock() should be undefined on UP.

#define spin_is_locked(l) panic()

should sort things out quickly ;-)