KeGetProcessorNumberFromIndex function (wdm.h)
The KeGetProcessorNumberFromIndex routine converts a systemwide processor index to a group number and a group-relative processor number.
Syntax
NTSTATUS KeGetProcessorNumberFromIndex(
[in] ULONG ProcIndex,
[out] PPROCESSOR_NUMBER ProcNumber
);
Parameters
[in] ProcIndex
A systemwide processor index. If a multiprocessor system contains a total of n logical processors, valid processor indexes range from 0 to n-1.
[out] ProcNumber
A pointer to a caller-allocated PROCESSOR_NUMBER structure into which the routine writes the group number and group-relative processor number of the processor that is identified by ProcIndex.
Return value
KeGetProcessorNumberFromIndex returns STATUS_SUCCESS if the call is successful. Possible error return values include the following:
| Return code | Description |
|---|---|
| STATUS_INVALID_PARAMETER | The ProcIndex parameter value is not a valid processor index. |
Remarks
This routine accepts as input a processor index that identifies the processor across the entire multiprocessor system. The output value is a PROCESSOR_NUMBER structure that identifies a processor by its group number and its processor number within the group.
For example, if a multiprocessor system contains two groups, and each group contains 64 logical processors, the processor numbers in each group range from 0 to 63, but the systemwide processor indexes range from 0 to 127.
To obtain the total number of active logical processors in the system, call the KeQueryActiveProcessorCountEx routine.
The KeGetProcessorIndexFromNumber routine converts a group number and a group-relative processor number to a systemwide processor index.
Examples
The following code example uses the KeQueryActiveProcessorCountEx and KeGetProcessorNumberFromIndex routines to enumerate all active logical processors in the system:
ULONG Count;
ULONG ProcIndex;
PROCESSOR_NUMBER ProcNumber;
Count = KeQueryActiveProcessorCountEx(ALL_PROCESSOR_GROUPS);
for (ProcIndex = 0; ProcIndex < Count; ProcIndex += 1)
{
KeGetProcessorNumberFromIndex(ProcIndex, &ProcNumber);
// Do something with the contents of ProcNumber.
...
}
The constant value ALL_PROCESSOR_GROUPS is defined in Winnt.h and Ntdef.h.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available in Windows 7 and later versions of Windows. |
| Target Platform | Universal |
| Header | wdm.h (include Ntddk.h, Wdm.h, Ntddk.h, Ntifs.h) |
| Library | NtosKrnl.lib |
| DLL | NtosKrnl.exe |
| IRQL | Any level |