search for: acpi_processor_driv

Hello, The following patches are a solution to a problem we have encountered when using the Xen hypervisor: - Need Pxx/Cxx states to save on power consumption when using Xen (we do want those datacenters to consume less power!), - Also need to figure out the Turbo mode so that the scheduler can properly boost a core for CPU bound guests. In essence the Xen hypervisor requires that

...as to be parsed by domain0 kernel ACPI sub-system, and then passed to hypervisor by hypercall. To make this happen, the key point is to add hook in the kernel ACPI sub-system. Fortunately, kernel already has good abstraction, and only several places need to add hook. To be more detail, there is an acpi_processor_driver (in drivers/acpi/processor_core.c) , which all the Cx/Px parsing event will go to. This driver will call its acpi processor event handler, e.g. add/remove, start/stop, notify to handle these events. These event handlers in turn will call some library functions (in drivers/acpi/processor_perflib.c...