MiSetPageFileAllocationBits

VOID __stdcall MiSetPageFileAllocationBits(_MMPAGING_FILE *PagingFile, UINT64 StartBit, UINT64 NumberOfPages){
  __int64 v4; 

  v4 = (unsigned int)NumberOfPages;
  RtlSetBits(&PagingFile->Bitmaps->AllocationBitmap, StartBit, NumberOfPages);
  PagingFile->FreeSpace -= v4;
}

Referenced by:

MiFindFreePageFileSpace
MiFindPageFileWriteCluster
MiGatherPagefilePages