Re: [PATCH -v8a 0/7] directed yield for Pause Loop Exiting

2011-02-07 Thread Avi Kivity
On 02/01/2011 04:44 PM, Rik van Riel wrote: When running SMP virtual machines, it is possible for one VCPU to be spinning on a spinlock, while the VCPU that holds the spinlock is not currently running, because the host scheduler preempted it to run something else. Both Intel and AMD CPUs have a

[PATCH -v8a 0/7] directed yield for Pause Loop Exiting

2011-02-01 Thread Rik van Riel
When running SMP virtual machines, it is possible for one VCPU to be spinning on a spinlock, while the VCPU that holds the spinlock is not currently running, because the host scheduler preempted it to run something else. Both Intel and AMD CPUs have a feature that detects when a virtual CPU is