Il 14/03/2014 09:30, Peter Zijlstra ha scritto:
Take the situation of 3 (v)CPUs where cpu0 holds the lock but is preempted. cpu1 queues, cpu2 queues. Then cpu1 gets preempted, after which cpu0 gets back online. The simple test-and-set lock will now let cpu2 acquire. Your queue however will just sit there spinning, waiting for cpu1 to come back from holiday. I think you're way over engineering this. Just do the simple test-and-set lock for virt && !paravirt (as I think Paolo Bonzini suggested RHEL6 already does).
Exactly. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
