typedef enum
{
    IopIoPriorityNotSet = 0,
    IopIoPriorityVeryLow = 1,
    IopIoPriorityLow = 2,
    IopIoPriorityNormal = 3,
    IopIoPriorityHigh = 4,
    IopIoPriorityCritical = 5,
    MaxIopIoPriorityTypes = 6
} IOP_PRIORITY_HINT;