On Mon, Jun 27, 2016 at 01:41:30PM -0400, Pan Xinhui wrote:
> @@ -118,8 +123,17 @@ bool osq_lock(struct optimistic_spin_queue *lock)
> while (!READ_ONCE(node->locked)) {
> /*
>* If we need to reschedule bail... so we can block.
> + * An
An over-committed guest with more vCPUs than pCPUs has a heavy overload
in osq_lock().
This is because vCPU A hold the osq lock and yield out, vCPU B wait
per_cpu node->locked to be set. IOW, vCPU B wait vCPU A to run and
unlock the osq lock. Such spinning is meaningless.
So lets use
