What is Madvise?

Madvise is a system call used to give directions to the kernel about an address range.

#include <sys/mman.h>
 
int madvise(void *addr, size_t length, int advice);

Some advice can include:

MADV_HUGEPAGE (enable huge pages for the range)
MADV_SEQUENTIAL (expect sequential accesses in the future)
MADV_WILLNEED (expect access in the future)
MADV_DONTNEED (don’t expect access in the future)
MADV_FREE (the application no longer requires the page(s), free them).