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Subject: Re: [PATCH] Replace completions with semaphores
From: Peter Zijlstra <peterz@infradead.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: Roland Dreier <rdreier@cisco.com>, Ingo Molnar <mingo@elte.hu>,
       Matthew Wilcox <matthew@wil.cx>, Ingo Oeser <ioe-lkml@rameria.de>,
       Daniel Walker <dwalker@mvista.com>, linux-kernel@vger.kernel.org,
       Linus Torvalds <torvalds@osdl.org>
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Date: Mon, 14 Apr 2008 19:54:33 +0200
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On Mon, 2008-04-14 at 19:46 +0200, Andi Kleen wrote:
> Peter Zijlstra <peterz@infradead.org> writes:
> >
> > Yeah, I would open code it.  But this is indeed a sane usage of the
> > counting semaphore because there is no priority inversion.
> 
> But when you open code that, how is it different from just having
> semaphores? 

Because we can then eventually get rid of semaphores, so those people
cannot mistakenly use them. Its just too easy to create prio inversion
with them around.