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SubjectRe: atomic_t (24 bits???)
On Tue, 25 Feb 2003, Daniel Jacobowitz wrote:

> On Tue, Feb 25, 2003 at 02:11:11PM -0500, Richard B. Johnson wrote:
> >
> > In ../linux/include/asm/atomic.h, for versions 2.4.18 and
> > above as far as I've checked, there are repeated warnings
> > "Note that the guaranteed useful range of an atomic_t is
> > only 24 bits."
> >
> > I fail to see any reason why as atomic_t is typdefed to a
> > volatile int which, on ix86 seems to be 32 bits.
> >
> > Does anybody know if this is just some old comments from a
> > previous atomic_t type of, perhaps, char[3]?
>
> There are other platforms where you can't reliably use the whole word.
> Some ARM atomic_t implementations are like this, although I don't know
> if the one in the kernel is.
>
> --
> Daniel Jacobowitz
> MontaVista Software Debian GNU/Linux Developer
>
Okay. Thanks.


Cheers,
Dick Johnson
Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).
Why is the government concerned about the lunatic fringe? Think about it.


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