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    SubjectRe: SMP syncronization on AMD processors (broken?)
    On Thu, 6 Oct 2005, Linus Torvalds wrote:
    >
    > If you want to notify another CPU that you want the spinlock, then you
    > need to set the "flag" variable _outside_ of the spinlock.
    >
    > Spinlocks are not fair, not by a long shot. They never have been, and they
    > never will. Fairness would be extremely expensive indeed.

    That reminds me: ought cond_resched_lock to be doing something more?

    int cond_resched_lock(spinlock_t *lock)
    {
    int ret = 0;

    if (need_lockbreak(lock)) {
    spin_unlock(lock);
    cpu_relax();
    ret = 1;
    spin_lock(lock);
    }
    -
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