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    SubjectRe: [PATCH RFC 3/4] Paravirtualized spinlock implementation for KVM guests
      On 07/26/2010 09:15 AM, Srivatsa Vaddagiri wrote:
    > Paravirtual spinlock implementation for KVM guests, based heavily on Xen guest's
    > spinlock implementation.
    >
    > +static void kvm_spin_unlock(struct arch_spinlock *lock)
    > +{
    > + struct kvm_spinlock *sl = (struct kvm_spinlock *)lock;
    > +
    > + ADD_STATS(released, 1);
    > +
    > + smp_wmb(); /* make sure no writes get moved after unlock */
    > + sl->lock = 0; /* release lock */
    > +}

    Wait, no wakeup?

    So it is a yield, not a sleep. I'm worried it could seriously impact
    fairness when one non-contending guest (or non-pv) is overcommitted
    together with a spin-yield guest.

    --
    error compiling committee.c: too many arguments to function



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