linux-kernel - Re: [PATCH] [keys] Always use key

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Date:	Wed, 19 Mar 2008 22:29:06 +0000
From:	David Howells <dhowells@...hat.com>
To:	Arun Raghavan <arunsr@....iitk.ac.in>
Cc:	dhowells@...hat.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] [keys] Always use key_get() to increment key refcount

Arun Raghavan <arunsr@....iitk.ac.in> wrote:

> Patch to use key_get() wherever the keys code manually increments the
> key refcount.
> 
> This should make debugging a little simpler for clients, since it
> becomes easier to track where a key's refcount changes.

The problem with this is that key_get() is not simply an atomic_inc().  You
end up introducing an extra conditional into each of these places where one is
not required.  Now it's possible that the compiler's optimiser is sufficiently
clever to get rid of them all, but do you guarantee that?

David
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