Patent ID: 7543161

Claim:
A method for tracking performance changes due to power management in a plurality of logical partitions of a data processing system having the plurality of logical partitions executing on one or more processors managed by a hypervisor, the method comprising: using a hypervisor, monitoring for a power management event in a first logical partition executing in a first processor; using the hypervisor, determining whether execution of the first logical partition on the first processor changes from a first performance level to a second performance level in response to the power management event; and using the hypervisor and responsive to the power management event, determining whether execution of a second logical partition executing on the first processor changes from a third performance level to a fourth performance level in response to the power management event; using the hypervisor, recording a first performance trace for the first logical partition that correlates a first change from the first performance level to the second performance level with a system state information when the first processor changes from the first performance state to the second performance state to the new performance level; using the hypervisor, recording a second performance trace for the second logical partition that correlates a second change from the third performance level to the fourth performance level with the system state information when the first processor changes from the third performance level to the fourth performance level.