struct MMVAD_FLAGS3

typedef struct _MMVAD_FLAGS3
{
     ULONG PreferredNode: 6;
     ULONG Spare: 2;
     ULONG SequentialAccess: 1;
     ULONG LastSequentialTrim: 15;
     ULONG Spare2: 8;
} MMVAD_FLAGS3, *PMMVAD_FLAGS3;

Windows Vista Kernel Structures