On Mon, Apr 22, 2013 at 4:08 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > I much prefer the entire series from Jeremy since it maintains the > ticket semantics and doesn't degrade the lock to unfair under > contention. > > Now I suppose there's a reason its not been merged yet and I suspect > its !paravirt hotpath impact which wasn't rightly justified or somesuch > so maybe someone can work on that or so.. dunno. > > In my paper, I comparable preemptable-lock and pv_lock on KVM from Raghu and Jeremy. Results show that: - preemptable-lock improves performance significantly without paravirt support - preemptable-lock can also be paravirtualized, which outperforms pv_lock, especially when overcommited by 3 or more - pv-preemptable-lock has much less performance variance compare to pv_lock, because it adapts to preemption within VM, other than using rescheduling that increase VM interference It would still be very interesting to conduct more experiments to compare these two, to see if the fairness enforced by pv_lock is mandatory, and if preemptable-lock outperforms pv_lock in most cases, and how do they work with PLE. --Jiannan -- 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
