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    SubjectRe: spin_lock forgets to clobber memory and other smp fixes [was
    kuznet@ms2.inr.ac.ru wrote:
    > > Well, now GCC does CSE across "asm" and will eliminate memory loads,
    > > even though it may not move them! I suspect it always did CSE across
    > > "asm" and we just never got hit by the bug.
    >
    > dummy_lock trick is equivalent to "memory" clobber.

    For GCC 2.7.2 yes. For current compilers with -fstrict-aliasing, no:
    the dummy_lock type doesn't alias with some other memory accesses.

    Longer term the compiler may well take into account the array size.

    Of course we still need the dummy_lock trick anyway.

    -- Jamie
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