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Subject: Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation
From: Thomas Gleixner <tglx@linutronix.de>
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To: Linus Torvalds <torvalds@osdl.org>
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Date: Sat, 17 Dec 2005 00:29:59 +0100
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On Fri, 2005-12-16 at 14:41 -0800, Linus Torvalds wrote:

> > You can still implement (chose a mechanism) a mutex on top - or in case
> > of lack of priority inheritance or debugging with exactly the same -
> > mechanism as a semaphore, but this does not change the semantical
> > difference at all.
> 
> "Friends don't let friends use priority inheritance".
> 
> Just don't do it. If you really need it, your system is broken anyway.

We are not talking about priority inheritance and its usefulness at all.

Fact is that you can implement two semanticaly different concurrency
controls with or on top of the same mechanism under given circumstances
(no debugging, no ...). But the reverse attempt is wrong by defintion.


	tglx