|| Linux Programmer's Manual
NAME mincore - determine whether pages are resident in memory
int mincore(void *
, unsigned char *
Feature Test Macro Requirements for glibc (see
(): _BSD_SOURCE || _SVID_SOURCE
() returns a vector that indicates whether pages of the calling process's virtual memory are resident in core (RAM), and so will not cause a disk access (page fault) if referenced. The kernel returns residency information about the pages starting at the address
, and continuing for
argument must be a multiple of the system page size. The
argument need not be a multiple of the page size, but since residency information is returned for whole pages,
is effectively rounded up to the next multiple of the page size. One may obtain the page size (
argument must point to an array containing at least
(length+PAGE_SIZE-1) / PAGE_SIZE
bytes. On return, the least significant bit of each byte will be set if the corresponding page is currently resident in memory, and be clear otherwise. (The settings of the other bits in each byte are undefined; these bits are reserved for possible later use.) Of course the information returned in
is only a snapshot: pages that are not locked in memory can come and go at any moment, and the contents of
may already be stale by the time this call returns.
RETURN VALUE On success,
mincore() returns zero. On error, -1 is returned, and
errno is set appropriately.
kernel is temporarily out of resources.
vec points to an invalid address.
addr is not a multiple of the page size.
length is greater than (
addr). (This could occur if a negative value is specified for
length, since that value will be interpreted as a large unsigned integer.) In Linux 2.6.11 and earlier, the error
EINVAL was returned for this condition.
length contained unmapped memory.
VERSIONS Available since Linux 2.3.99pre1 and glibc 2.2.
mincore() is not specified in POSIX.1-2001, and it is not available on all UNIX implementations.
BUGS Before kernel 2.6.21,
mincore() did not return correct information for
MAP_PRIVATE mappings, or for nonlinear mappings (established using
COLOPHON This page is part of release 3.53 of the Linux
man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.