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From: Thomas Gleixner <tglx@linutronix.de>
To: Kumar Gala <galak@kernel.crashing.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Linux-Kernel List <linux-kernel@vger.kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	linuxppc-dev list <linuxppc-dev@ozlabs.org>,
	Ingo Molnar <mingo@elte.hu>
Subject: Re: spin_is_locked() broken for uniprocessor?
Date: Wed, 19 Aug 2009 00:24:02 +0200 (CEST)	[thread overview]
Message-ID: <alpine.LFD.2.00.0908190022570.3361@localhost.localdomain> (raw)
In-Reply-To: <DE9C9034-D2CE-4D21-93D9-A10FE2580920@kernel.crashing.org>

On Tue, 18 Aug 2009, Kumar Gala wrote:
> I just want to validate that what I'm seeing (for UP, non-debug features):
> 
> spin_is_locked() is defined as:
> 
> include/linux/spinlock.h:#define spin_is_locked(lock)
> __raw_spin_is_locked(&(lock)->raw_lock)
> 
> for UP that should get us:
> 
> include/linux/spinlock_up.h:#define __raw_spin_is_locked(lock)  ((void)(lock),
> 0)
> 
> 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.

Thanks,

	tglx

  reply	other threads:[~2009-08-18 22:24 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-18 22:09 spin_is_locked() broken for uniprocessor? Kumar Gala
2009-08-18 22:24 ` Thomas Gleixner [this message]
2009-08-19  9:38   ` David Howells
2009-08-19  9:41     ` Peter Zijlstra
2009-08-27  9:32       ` Benjamin Herrenschmidt
2009-08-19 10:53     ` Alan Cox
2009-08-19 11:16       ` Leon Woestenberg
2009-08-19 11:23         ` Peter Zijlstra

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