GET_HUGE_PAGES(3)GET_HUGE_PAGES(3)NAME
get_huge_pages, free_huge_pages - Allocate and free hugepages
SYNOPSIS
#include <hugetlbfs.h>
void *get_huge_pages(size_t len, ghp_t flags);
void free_huge_pages(void *ptr);
DESCRIPTIONget_huge_pages() allocates a memory region len bytes in size backed by
hugepages. Hugepages may be of benefit to applications that use large
amounts of address space and suffer a performance hit due to TLB
misses. Wall-clock time or oprofile can be used to determine if there
is a performance benefit from using hugepages or not.
The len parameter must be hugepage-aligned. In the current implementa‐
tion, only the default hugepage size may be allocated via this func‐
tion. Use gethugepagesize to discover what the alignment should be.
The flags argument changes the behaviour of the function. Flags may be
or'd together.
GHP_DEFAULT
Allocate a region of memory of the requested length backed by
hugepages of the default hugepage size. Return NULL if suffi‐
cient pages are not available
free_huge_pages() frees a region of memory allocated by
get_huge_pages(). The behaviour of the function if another pointer is
used, valid or otherwise, is undefined.
RETURN VALUE
On success, a pointer is returned to the allocated memory. On error,
NULL is returned. errno will be set based on what the failure of mmap()
was due to.
SEE ALSOoprofile(1) , gethugepagesize(3) , get_hugepage_region(3) , lib‐
hugetlbfs(7)AUTHORS
libhugetlbfs was written by various people on the libhugetlbfs-devel
mailing list.
October 8, 2008 GET_HUGE_PAGES(3)