MASTER SLAVE QPI PROTOCOL FOR COORDINATED IDLE POWER MANAGEMENT IN GLUELESS AND CLUSTERED SYSTEMS

摘要

Methods, apparatus, and systems for implementing coordinated idle power management in glueless and clustered systems. Components for facilitating coordination of package idle power state between sockets in a glueless system such as a server platform include a master entity in one socket (i.e., processor) and a slave entity in each socket participating in the power management coordination. Each slave collects idle status inputs from various sources and when the socket cores are sufficiently idle, it makes a request to the master to enter a deeper idle power state. The master coordinates global power management operations in response to the slave requests, including broadcasting a command with a target latency to all of the slaves to allow the processors to enter reduced power (i.e., idle) states in a coordinated manner. Communications between the entities is facilitated using messages transported over existing interconnects and corresponding protocols, enabling the benefits associated with the disclosed embodiments to be implemented using existing designs.