Messages in this thread | | | Date | Mon, 13 Sep 2004 22:18:26 +0200 (CEST) | From | Roman Zippel <> | Subject | Re: 2.6.9-rc1-mm4 sparc reiser4 build broken - undefined atomic_sub_and_test |
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Hi,
On Mon, 13 Sep 2004, Tonnerre wrote:
> On Mon, Sep 13, 2004 at 06:03:28PM +0200, Roman Zippel wrote: > > +#define atomic_add_and_test(i,v) (atomic_add_return((i), (v)) == 0) > > +#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) > > This is no longer atomic, is it? I mean, there's no guarantee that the > atomic_add_return and the comparison are executed without > interruption, is there?
Only the read/write access needs to be atomic, when the comparison happens is irrelevant.
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