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    SubjectRe: [PATCH 06/18] x86/ticketlock: make __ticket_spin_trylock common
    On Wed, Aug 24, 2011 at 1:00 PM, Andi Kleen <> wrote:
    > Can't we just get rid of the small ticket size code path?
    > I couldn't benchmark any difference between the two last time
    > I tried.

    The small locks aren't any faster. They are just smaller.

    Many data structures have spinlocks inside of them, and the smaller
    spinlock *should* be able to result in smaller data structures.

    Of course, that assumes that they have been packed correctly. And they
    seldom are ;(

    Looking at 'struct task_struct', for example, the spinlocks there
    aren't next to each other, and have pointers and 'unsigned int's
    around them, so rather than shrinking the data structure, it just
    results in holes.


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