getpagesizes(3) [centos man page]

GETPAGESIZES(3) 					     Library Functions Manual						   GETPAGESIZES(3)

NAME

       getpagesizes - Get the system supported huge page sizes

SYNOPSIS

       #include <hugetlbfs.h>

       int getpagesizes(long pagesizes[], int n_elem);

DESCRIPTION

       The  getpagesizes()  function  returns  either the number of system supported page sizes or the sizes  themselves. If pagesizes is NULL and
       n_elem is 0, then the number of pages the system supports is returned. Otherwise, pagesizes is filled with at most n_elem page sizes.

RETURN VALUE

       On success, either the number of page sizes supported by the system or the number of page sizes stored in pagesizes is returned.  On  fail-
       ure, -1 is returned and errno is set appropriately.

ERRORS

       EINVAL n_elem is less than zero or n_elem is greater than zero and pagesizes is NULL.

       Also see opendir(3) for other possible values for errno. This error occurs when the sysfs directory exists but cannot be opened.

NOTES

       This  call will return all page sizes as reported by the kernel.  Not all of these sizes may be usable by the programmer since mount points
       may not be available for the huge page sizes.  To test whether a size will be usable by libhugetlbfs, hugetlbfs_find_path_for_size() can be
       called on a specific size to see if a mount point is configured.

SEE ALSO

       oprofile(1), opendir(3), gethugepagesizes(3), libhugetlbfs(7)

AUTHORS

       libhugetlbfs was written by various people on the libhugetlbfs-devel mailing list.

								 October 10, 2008						   GETPAGESIZES(3)

getpagesizes(3C)					   Standard C Library Functions 					  getpagesizes(3C)

NAME

       getpagesizes - get system supported page sizes

SYNOPSIS

       #include <sys/mman.h>

       int getpagesizes(size_t pagesize[], int nelem);

DESCRIPTION

       The getpagesizes() function returns either the number of different page sizes supported by the system or the actual sizes themselves.  When
       called with nelem as 0 and pagesize as NULL, getpagesizes() returns the number of supported page sizes. Otherwise, up to nelem  page  sizes
       are  retrieved and assigned to successive elements  of pagesize[].  The return value is the number of page sizes retrieved and set in page-
       size[].

RETURN VALUES

       Upon successful completion, the number of pagesizes supported or actually retrieved is returned. Otherwise, -1 is returned and errno is set
       to indicate the error.

ERRORS

       The getpagesizes() function will fail if:

       EINVAL	       The nelem argument is less than 0 or pagesize is NULL but nelem is non-zero.

USAGE

       The  getpagesizes()  function returns all the page sizes for which the hardware and system software provide support for the memcntl(2) com-
       mand MC_HAT_ADVISE. Not all processors support all page sizes or combinations of page sizes with equal efficiency. Applications programmers
       should take this into consideration when using getpagesizes().

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       memcntl(2), mmap(2), getpagesize(3C), attributes(5)

SunOS 5.10							    14 May 2001 						  getpagesizes(3C)