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    SubjectRe: [patch 04/15] Generic Mutex Subsystem, add-atomic-call-func-x86_64.patch
    On Tue, 20 Dec 2005, Arjan van de Ven wrote:

    > on x86 the fastpath is the same for both basically.. is there a
    > fundamental reason it can't be for ARM?

    ARM prior ARM architecture level 6 (which means about 99% of all ARM
    processors in the field currently) cannot do an atomic
    decrement/increment. It must be done manually with interrupt disabled.

    The only truly atomic instruction it has is a swap which lays itself
    pretty well for mutex support.


    Nicolas
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