MINCORE(2) System Calls MINCORE(2)

NAME

mincore - determine residency of memory pages

SYNOPSIS

#include <sys/types.h>

int mincore(caddr_t addr, size_t len, char *vec);

DESCRIPTION

The mincore() function determines the residency of the memory pages
in the address space covered by mappings in the range [addr, addr +
len]. The status is returned as a character-per-page in the character
array referenced by *vec (which the system assumes to be large enough
to encompass all the pages in the address range). The least
significant bit of each character is set to 1 to indicate that the
referenced page is in primary memory, and to 0 to indicate that it is
not. The settings of other bits in each character are undefined and
may contain other information in future implementations.


Because the status of a page can change between the time mincore()
checks and returns the information, returned information might be
outdated. Only locked pages are guaranteed to remain in memory; see
mlock(3C).

RETURN VALUES

Upon successful completion, mincore() returns 0. Otherwise, -1 is
returned and errno is set to indicate the error.

ERRORS

The mincore() function will fail if:

EFAULT
The vec argument points to an illegal address.


EINVAL
The addr argument is not a multiple of the page size as
returned by sysconf(3C), or the len argument has a value
less than or equal to 0.


ENOMEM
Addresses in the range [addr, addr + len] are invalid for
the address space of a process or specify one or more pages
which are not mapped.

SEE ALSO

mmap(2), mlock(3C), sysconf(3C)

August 12, 1990 MINCORE(2)