NdisGroupActiveProcessorMask function (ndis.h)

Article
02/22/2024

The NdisGroupActiveProcessorMask function returns the currently active processor mask for the specified group.

Syntax

KAFFINITY NdisGroupActiveProcessorMask(
  USHORT Group
);

Parameters

Group

A USHORT value that identifies a processor group in the local computer system.

Return value

NdisGroupActiveProcessorMask returns the currently active processor mask for the specified group as a KAFFINITY bitmap. In an environment that allows for hot-add functionality, this bitmap can change during runtime.

Remarks

An NDIS driver might call the NdisGroupActiveProcessorMask function during initialization before it allocates resources.

The KAFFINITY value that NdisGroupActiveProcessorMask returns can change at runtime on SKUs that support hot-add functionality for CPUs.

Note NDIS drivers should not use the NdisSystemProcessorCount function to retrieve the number of currently active processors. Also, NDIS 6.20 and later drivers should not use the NdisSystemActiveProcessorCount function because it only returns the processor count and provides the affinity mask as an out parameter, for processor group 0.

To obtain an active processor count, call the NdisGroupActiveProcessorCount function.

Requirements

Requirement	Value
Minimum supported client	Supported in NDIS 6.20 and later.
Target Platform	Universal
Header	ndis.h (include Ndis.h)
Library	Ndis.lib
IRQL	Any level