On Mon, Feb 24, 2014 at 8:37 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> So yes, the atomic_read() would be ordered wrt '*ptr' (getting 'q')
> _and_ '**ptr' (getting 'i'), but nothing else - including just the
> aliasing access of dereferencing 'i' directly.
Btw, what CPU architects and memory ordering guys tend to do in
documentation is give a number of "litmus test" pseudo-code sequences
to show the effects and intent of the language.
I think giving those kinds of litmus tests for both "this is ordered"
and "this is not ordered" cases like the above is would be a great
clarification. Partly because the language is going to be somewhat
legalistic and thus hard to wrap your mind around, and partly to
really hit home the *intent* of the language, which I think is
actually fairly clear to both compiler writers and to programmers.
Linus
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