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    SubjectRe: test13-pre5
    On Sun, Dec 31, 2000 at 09:27:23AM -0800, Linus Torvalds wrote:
    > On Sun, 31 Dec 2000, Andi Kleen wrote:
    > >
    > > Sounds good. It could also be controlled by a CONFIG_SPACE_EFFICIENT for
    > > embedded systems, where you could trade a bit of CPU for less memory overhead
    > > even on systems where u8 is slow and atomicity doesn't come into play
    > > because it's UP anyways.
    >
    > UP has nothing to do with it.
    > The alpha systems I remember this problem on were all SMP.

    Actually nothing SMP specific in that problem sphere.
    Alpha has load-locked/store-conditional pair for
    this type of memory accesses to automatically detect,
    and (conditionally) restart the operation - to form
    classical ``locked-read-modify-write'' operations.

    In what situations the compiler will use those instructions,
    that I don't know. Volatiles, very least, use them.
    Will closely packed bytes be processed with it without
    them being volatiles ? How about bitfields ?

    Newer Alphas have byte/short load/store instructions,
    so things really aren't that straight-forward...

    ....
    > I don't think it's a good diea.
    >
    > Linus

    /Matti Aarnio
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