1MADV_NORMAL
2MADV_RANDOM
3MADV_SEQUENTIAL
4MADV_WILLNEED
5MADV_DONTNEED
6MADV_REMOVE
7MADV_DONTFORK
8MADV_DOFORK
9MADV_HWPOISON
10MADV_SOFT_OFFLINE
11MADV_MERGEABLE
12MADV_UNMERGEABLE
13MADV_HUGEPAGE
14MADV_NOHUGEPAGE
15MADV_DONTDUMP
16MADV_DODUMP
17