Advanced Configuration and Power Interface Specification

Processor Configuration and Control
8.5.2 OSPM _OST Evaluation
When processing of the _PUR object evaluation completes, OSPM evaluates the _OST object, if
present under the Processor Aggregator device, to convey _PUR evaluation status to the platform.
_OST arguments specific to _PUR evaluation are described below.
Arguments: (3)
Arg0 – Source Event (Integer) : 0x80
Arg1 – Status Code (Integer) : see below
Arg2 – Idled Procs (Buffer) : see below
Return Value:
None
Argument Information:
Arg1 – Status Code
0: success – OSPM idled the number of logical processors indicated by the value of Arg2
1: no action was performed
Arg2 – A 4-byte buffer that represents a DWORD that is the number of logical processors that are
now idled)
The platform may request a number of logical processors to be idled that exceeds the available
number of logical processors that can be idled from an OSPM context for the following reasons:
• The requested number is larger than the number of logical processors currently defined.
• Not all the defined logical processors were onlined by the OS (for example. for licensing
reasons)
Logical processors critical to OS function (for example, the BSP) cannot be idled.
Version 6.0 495