struct PO_NOTIFY_ORDER_LEVEL

typedef struct _PO_NOTIFY_ORDER_LEVEL
{
     ULONG DeviceCount;
     ULONG ActiveCount;
     LIST_ENTRY WaitSleep;
     LIST_ENTRY ReadySleep;
     LIST_ENTRY ReadyS0;
     LIST_ENTRY WaitS0;
} PO_NOTIFY_ORDER_LEVEL, *PPO_NOTIFY_ORDER_LEVEL;

Windows Vista Kernel Structures