mmap with huge page

Hi,According to the instruction, I have to mount a huge directory to hugetlbfs and create file in the huge directory to use the mmap huge page feature. But the issue is that, the files in the huge directory takes up the huge pages configured throughvm.nr_hugepages = even the files are not used. When the total size of the files in the huge directory = vm.nr_hugepages * huge page size, then mmap would fail with 'can not allocate memory' if the file to be  mapped is in the huge dir or the call has HUGEPAGETLB flag. Basically, I have to move the files off of the huge directory to free up huge pages. Am I missing anything here? Thanks, David