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 pagesize[].

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) command
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)


May 14, 2001 GETPAGESIZES(3C)