To: "Bryan O'Sullivan" <bos@pathscale.com>
Cc: rolandd@cisco.com, gregkh@suse.de, akpm@osdl.org, davem@davemloft.net,
       linux-kernel@vger.kernel.org, openib-general@openib.org
Subject: Re: [PATCH 9 of 20] ipath - char devices for diagnostics and lightweight subnet management
References: <28bb276205de498d0b5c.1141950939@eng-12.pathscale.com>
	<adaslprcelg.fsf@cisco.com>
	<1141951622.10693.85.camel@serpentine.pathscale.com>
From: Roland Dreier <rdreier@cisco.com>
Date: Thu, 09 Mar 2006 16:52:47 -0800
In-Reply-To: <1141951622.10693.85.camel@serpentine.pathscale.com> (Bryan O'Sullivan's message of "Thu, 09 Mar 2006 16:47:02 -0800")
Message-ID: <adaoe0fce8w.fsf@cisco.com>
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    Bryan> It's read outside of this file, without a lock held.

I missed the other reference in another patch.  But the central point
still stands: if all you do is atomic_set() and atomic_read(), then
using atomic_t doesn't buy you anything.  Just look at what
atomic_read() expands to -- using it isn't protecting you against
anything, so either you have a race, or you were safe without
atomic_t.  The only point to atomic_t is so that you can safely do
read-modify-write things like atomic_inc().

 - R.
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