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    SubjectRe: page table lock patch V15 [0/7]: overview
    Hi,

    On Fri, 14 Jan 2005, Andi Kleen wrote:

    > > But there might be a loss in the UP case. Spinlocks are optimized away,
    > > but your cmpxchg emulation enables/disables interrupts with every access.
    >
    > Only for 386s and STI/CLI is quite cheap there.

    But it's still not free and what about other archs? Why not just check
    __HAVE_ARCH_CMPXCHG and provide a replacement, which is guaranteed cheaper
    if no interrupt synchronisation is needed.

    bye, Roman
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