Re: [PATCH 6/24] make atomic_read() behave consistently on frv

Segher Boessenkool
2007-08-15T19:48:27Z

>>> Well if there is only one memory location involved, then smp_rmb()
>>> isn't
>>> going to really do anything anyway, so it would be incorrect to use
>>> it.
>>
>> rmb() orders *any* two reads; that includes two reads from the same
>> location.
>
> If the two reads are to the same location, all CPUs I am aware of
> will maintain the ordering without need for a memory barrier.

That's true of course, although there is no real guarantee for that.

Segher