Re: [RFC -v4 PATCH 0/3] directed yield for Pause Loop Exiting

2011-01-13 Thread Avi Kivity
On 01/13/2011 07:21 AM, 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

[RFC -v4 PATCH 0/3] directed yield for Pause Loop Exiting

2011-01-12 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