Patent ID: 7647509

Claim:
An apparatus to support power management among multiple processing system partitions, the apparatus comprising: a first interrupt handler to execute in a first partition of a processing system, the first interrupt handler to receive a standby command from an operating system (OS) of the processing system, wherein the processing system includes a first processing unit for the first partition and a second processing unit for a second partition; the first interrupt handler to cause the first processing unit to transition into a reduced power mode in response to the standby command; and a second interrupt handler to detect a wake event at the second partition; the second interrupt handler to cause the first processing unit to transition out of the reduced power mode in response to detecting the wake event, wherein the standby command comprises an interrupt generated by the OS to request a transition to a sleep mode; the first processing unit to transition into the reduced power mode by entering an idle loop within the first interrupt handler; the first partition to determine, from within the idle loop, whether the first partition has been released from the low power state; and the first partition to exit the idle loop and the first interrupt handler, in response to a determination that the first partition has been released from the low power state.