On 20.12.2011, at 11:37, Paul Mackerras wrote: > This adds code to measure "stolen" time per virtual core in units of > timebase ticks, and to report the stolen time to the guest using the > dispatch trace log (DTL). The guest can register an area of memory > for the DTL for a given vcpu. The DTL is a ring buffer where KVM > fills in one entry every time it enters the guest for that vcpu. > > Stolen time is measured as time when the virtual core is not running, > either because the vcore is not runnable (e.g. some of its vcpus are > executing elsewhere in the kernel or in userspace), or when the vcpu > thread that is running the vcore is preempted. This includes time > when all the vcpus are idle (i.e. have executed the H_CEDE hypercall), > which is OK because the guest accounts stolen time while idle as idle > time. > > Each vcpu keeps a record of how much stolen time has been reported to > the guest for that vcpu so far. When we are about to enter the guest, > we create a new DTL entry (if the guest vcpu has a DTL) and report the > difference between total stolen time for the vcore and stolen time > reported so far for the vcpu as the "enqueue to dispatch" time in the > DTL entry. > > Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx> This patch makes sense and looks good to me :) Alex -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
