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    SubjectRe: Can context switches be faster?
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    Phillip Susi wrote:
    > John Richard Moser wrote:
    >> Can context switches be made faster? This is a simple question, mainly
    >> because I don't really understand what happens during a context switch
    >> that the kernel has control over (besides storing registers).
    >>
    >
    > Besides saving the registers, the expensive operation in a context
    > switch involves flushing caches and switching page tables. This can be
    > avoided if the new and old processes both share the same address space.
    >

    i.e. this can be avoided when switching to threads in the same process.

    How does a page table switch work? As I understand there are PTE chains
    which are pretty much linked lists the MMU follows; I can't imagine this
    being a harder problem than replacing the head. I'd imagine the head
    PTE would be something like a no-access page that's not really mapped to
    anything so exchanging it is pretty much exchanging its "next" pointer?


    >
    >

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