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Date: Sat, 15 May 2004 23:54:01 +0100
From: Jamie Lokier <jamie@shareable.org>
To: "Richard B. Johnson" <root@chaos.analogic.com>
Cc: Al Niessner <Al.Niessner@jpl.nasa.gov>, linux-kernel@vger.kernel.org
Subject: Re: atomic_t and atomic_inc
Message-ID: <20040515225401.GA17504@mail.shareable.org>
References: <1082660320.28900.193.camel@morte.jpl.nasa.gov> <Pine.LNX.4.53.0404221641120.940@chaos>
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Richard B. Johnson wrote:
> Type atomic_t is an integer that can be accessed in memory
> with an uninterruptible instruction. This limits the atomic_t
> type in 32-bit machines to 32-bits, in 64-bit machines to 64-bits,
> etc. It has nothing to do with wrap-around. If you increment
> 0xffffffff it becomes 0 even it it's an atomic type.

Note that atomic_t used to be 24 bits on Sparc.  It isn't any more, though.

-- Jame