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    SubjectRe: [PATCH 0/2] jump label: 2.6.38 updates
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    >> What CPU family are we talking about here?  For cache coherent CPUs,
    >> cache coherence really is supposed to work, even for mixed atomic and
    >> non-atomic instructions to the same variable.
    >
    > I'm really curious to know which CPU families too. I've used git blame
    > to see where these lwz/stw instructions were added to powerpc, and it
    > points to:
    >
    > commit 9f0cbea0d8cc47801b853d3c61d0e17475b0cc89

    > So let's ping the relevant people to see if there was any reason for
    > making these atomic read/set operations different from other
    > architectures in the first place.

    lwz is a simple 32-bit load. On PowerPC, such a load is guaranteed
    to be atomic (except some unaligned cases). stw is similar, for stores.
    These are the normal insns, not ll/sc or anything.

    At the time, volatile tricks were used to make the accesses atomic; this
    patch changed that. Result is (or should be!) better code generation.

    Is there a problem with it?


    Segher



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