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    SubjectRe: why are some atomic_t's not volatile, while most are?
    Chris Friesen wrote:
    > Chris Snook wrote:
    >
    >> This is not a problem, since indirect references will cause the CPU to
    >> fetch the data from memory/cache anyway.
    >
    > Isn't Zan's sample code (that shows the problem) already using indirect
    > references?

    Yeah, I misinterpreted his conclusion. I thought about this for a
    while, and realized that it's perfectly legal for the compiler to re-use
    a value obtained from atomic_read. All that matters is that the read
    itself was atomic. The use (or non-use) of the volatile keyword is
    really more relevant to the other atomic operations. If you want to
    guarantee a re-read from memory, use barrier(). This, incidentally,
    uses volatile under the hood.

    -- Chris
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