Section (2) mincore
mincore — determine whether pages are resident in memory
#include <unistd.h> #include <sys/mman.h>
|unsigned char *vec
mincore() returns a vector
that indicates whether pages of the calling process_zsingle_quotesz_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
addr, and continuing
must be a multiple of the system page size. The
length argument need not be a
multiple of the page size, but since residency information is
returned for whole pages,
length is effectively rounded
up to the next multiple of the page size. One may obtain the
page size (
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
vec is only a snapshot: pages
that are not locked in memory can come and go at any moment,
and the contents of
vec may already be stale by the
time this call returns.
returns zero. On error, −1 is returned, and
errno is set appropriately.
EAGAIN kernel is temporarily out of resources.
vecpoints to an invalid address.
addris not a multiple of the page size.
lengthis 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.
lengthcontained unmapped memory.
mincore() is not specified
in POSIX.1, and it is not available on all UNIX
Before kernel 2.6.21,
mincore() did not return correct
mappings, or for nonlinear mappings (established using
This page is part of release 4.16 of the Linux
man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
Copyright (C) 2001 Bert Hubert <ahuds9a.nl>
and Copyright (C) 2007 Michael Kerrisk <mtk.manpagesgmail.com>
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Since the Linux kernel and libraries are constantly changing, this
manual page may be incorrect or out-of-date. The author(s) assume no
responsibility for errors or omissions, or for damages resulting from
the use of the information contained herein. The author(s) may not
have taken the same level of care in the production of this manual,
which is licensed free of charge, as they might when working
Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
Created Sun Jun 3 17:23:32 2001 by bert hubert <ahuds9a.nl>
Slightly adapted, following comments by Hugh Dickins, aeb, 2001-06-04.
Modified, 20 May 2003, Michael Kerrisk <mtk.manpagesgmail.com>
Modified, 30 Apr 2004, Michael Kerrisk <mtk.manpagesgmail.com>
2005-04-05 mtk, Fixed error descriptions
after message from <gordon.jinintel.com>
2007-01-08 mtk, rewrote various parts