typedef struct _CONTROL_AREA
{
     PSEGMENT Segment;
     LIST_ENTRY DereferenceList;
     ULONG NumberOfSectionReferences;
     ULONG NumberOfPfnReferences;
     ULONG NumberOfMappedViews;
     ULONG NumberOfUserReferences;
     ULONG u;
     ULONG u1;
     EX_FAST_REF FilePointer;
     LONG ControlAreaLock;
     ULONG StartingFrame;
     PMI_SECTION_CREATION_EVENT WaitingForDeletion;
     BYTE u2[12];
     INT64 LockedPages;
} CONTROL_AREA, *PCONTROL_AREA;

Windows Vista Kernel Structures