IO_PRIORITY_HINT enumeration (wdm.h)

The IO_PRIORITY_HINT enumeration type specifies the priority hint for an IRP.

Syntax

typedef enum _IO_PRIORITY_HINT {
  IoPriorityVeryLow,
  IoPriorityLow,
  IoPriorityNormal,
  IoPriorityHigh,
  IoPriorityCritical,
  MaxIoPriorityTypes
} IO_PRIORITY_HINT;

Constants

IoPriorityVeryLow Specifies the lowest possible priority hint level. The system uses this value for background I/O operations.
IoPriorityLow Specifies a low-priority hint level.
IoPriorityNormal Specifies a normal-priority hint level. This value is the default setting for an IRP.
IoPriorityHigh Specifies a high-priority hint level. This value is reserved for use by the system.
IoPriorityCritical Specifies the highest-priority hint level. This value is reserved for use by the system.
MaxIoPriorityTypes Marks the limit for priority hints. Any priority hint value must be less than MaxIoPriorityTypes.

Remarks

For more information about priority hints, see Using IRP Priority Hints.

Requirements

Requirement	Value
Header	wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)

See also

IoGetIoPriorityHint

IoSetIoPriorityHint