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

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.

Consider that smp_rmb basically will do anything from flushing the

pipeline to invalidating loads speculatively executed out of order. AFAIK it will not control the visibility of stores coming from other CPUs (that

is up to the cache coherency).

The writer side should typically use wmb() whenever the reader side
uses rmb(), sure.


Segher

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