typedef struct _SUBSECTION
{
    CONTROL_AREA *ControlArea;
    MMPTE *SubsectionBase;
    SUBSECTION *NextSubsection;
    unsigned long PtesInSubsection;
    union
    {
        unsigned long UnusedPtes;
        MM_AVL_TABLE *GlobalPerSessionHead;
    };
    union
    {
        unsigned long LongFlags;
        MMSUBSECTION_FLAGS SubsectionFlags;
    } u;
    unsigned long StartingSector;
    unsigned long NumberOfFullSectors;
} SUBSECTION, *PSUBSECTION;