On Sun, 29 Mar 2015, Hugh Dickins wrote:

quoted

munmap(2) of hugetlb memory requires a length that is hugepage aligned,
otherwise it may fail.  Add this to the documentation.

Thanks for taking this on, David.  But although munmap(2) is the one
Davide called out, it goes beyond that, doesn't it?  To mprotect and
madvise and ...

Yes, good point, munmap(2) isn't special in this case, the alignment to 
the native page size of the platform should apply to madvise, mbind, 
mincore, mlock, mprotect, remap_file_pages, etc.

I'd hesitate to compile any authoritative list on the behavior in 
Documentation/vm/hugetlbpage.txt since it would exclude future extensions, 
but I'll update it to be more inclusive of other mm syscalls rather than 
specify only munmap(2).