1 .\" Copyright (C) 2001 Bert Hubert <ahu@ds9a.nl>
2 .\" and Copyright (C) 2007 Michael Kerrisk <mtk.manpages@gmail.com>
4 .\" %%%LICENSE_START(VERBATIM)
5 .\" Permission is granted to make and distribute verbatim copies of this
6 .\" manual provided the copyright notice and this permission notice are
7 .\" preserved on all copies.
9 .\" Permission is granted to copy and distribute modified versions of this
10 .\" manual under the conditions for verbatim copying, provided that the
11 .\" entire resulting derived work is distributed under the terms of a
12 .\" permission notice identical to this one.
14 .\" Since the Linux kernel and libraries are constantly changing, this
15 .\" manual page may be incorrect or out-of-date. The author(s) assume no
16 .\" responsibility for errors or omissions, or for damages resulting from
17 .\" the use of the information contained herein. The author(s) may not
18 .\" have taken the same level of care in the production of this manual,
19 .\" which is licensed free of charge, as they might when working
22 .\" Formatted or processed versions of this manual, if unaccompanied by
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26 .\" Created Sun Jun 3 17:23:32 2001 by bert hubert <ahu@ds9a.nl>
27 .\" Slightly adapted, following comments by Hugh Dickins, aeb, 2001-06-04.
28 .\" Modified, 20 May 2003, Michael Kerrisk <mtk.manpages@gmail.com>
29 .\" Modified, 30 Apr 2004, Michael Kerrisk <mtk.manpages@gmail.com>
30 .\" 2005-04-05 mtk, Fixed error descriptions
31 .\" after message from <gordon.jin@intel.com>
32 .\" 2007-01-08 mtk, rewrote various parts
34 .TH MINCORE 2 2017-05-03 "Linux" "Linux Programmer's Manual"
36 mincore \- determine whether pages are resident in memory
38 .B #include <unistd.h>
40 .B #include <sys/mman.h>
42 .BI "int mincore(void *" addr ", size_t " length ", unsigned char *" vec );
45 Feature Test Macro Requirements for glibc (see
46 .BR feature_test_macros (7)):
52 Glibc 2.19 and earlier:
53 _BSD_SOURCE || _SVID_SOURCE
56 returns a vector that indicates whether pages
57 of the calling process's virtual memory are resident in core (RAM),
58 and so will not cause a disk access (page fault) if referenced.
59 The kernel returns residency information about the pages
60 starting at the address
68 argument must be a multiple of the system page size.
71 argument need not be a multiple of the page size,
72 but since residency information is returned for whole pages,
74 is effectively rounded up to the next multiple of the page size.
75 One may obtain the page size
78 .IR sysconf(_SC_PAGESIZE) .
82 argument must point to an array containing at least
83 .I "(length+PAGE_SIZE\-1) / PAGE_SIZE"
86 the least significant bit of each byte will be set if
87 the corresponding page is currently resident in memory,
88 and be clear otherwise.
89 (The settings of the other bits in each byte are undefined;
90 these bits are reserved for possible later use.)
91 Of course the information returned in
93 is only a snapshot: pages that are not
94 locked in memory can come and go at any moment, and the contents of
96 may already be stale by the time this call returns.
101 On error, \-1 is returned, and
103 is set appropriately.
106 kernel is temporarily out of resources.
110 points to an invalid address.
114 is not a multiple of the page size.
119 .RI ( TASK_SIZE " \- " addr ).
120 (This could occur if a negative value is specified for
122 since that value will be interpreted as a large
124 In Linux 2.6.11 and earlier, the error
126 was returned for this condition.
134 contained unmapped memory.
136 Available since Linux 2.3.99pre1 and glibc 2.2.
139 is not specified in POSIX.1,
140 and it is not available on all UNIX implementations.
141 .\" It is on at least NetBSD, FreeBSD, OpenBSD, Solaris 8,
142 .\" AIX 5.1, SunOS 4.1
146 .\" function first appeared in 4.4BSD.
148 Before kernel 2.6.21,
150 did not return correct information for
152 mappings, or for nonlinear mappings (established using
153 .BR remap_file_pages (2)).
154 .\" Linux (up to now, 2.6.5),
156 .\" does not return correct information for MAP_PRIVATE mappings:
157 .\" for a MAP_PRIVATE file mapping,
159 .\" returns the residency of the file pages, rather than any
160 .\" modified process-private pages that have been copied on write;
161 .\" for a MAP_PRIVATE mapping of
164 .\" always reports pages as nonresident;
165 .\" and for a MAP_PRIVATE, MAP_ANONYMOUS mapping,
167 .\" always fails with the error
174 .BR posix_fadvise (2),
175 .BR posix_madvise (3)