Il 17/12/2013 10:32, Arthur Chunqi Li ha scritto: > Hi Jan and Paolo, > > I've tried to use preemption timer in KVM to trap vcpu regularly, but > there's something unexpected. I run a VM with 4 vcpus and give them > the same preemption timer value (e.g. 1000000) with all bits set > (activate/save bits), then reset the value in preemption time-out > handler. > > Thus I expected these vcpus trap regularly in some special turns. But > I found that when the VM is not busy, some vcpus are trapped much less > frequently than others. In Intel SDM, I noticed that preemption timer > is only related to TSC, and I think all the vcpus should trap in a > similar frequency. Does the preemption timer testcase pass on your machine? The preemption timer is known to have bugs. 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
