1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)mincore.2 8.1 (Berkeley) 6/9/93 29.\" 30.Dd August 23, 2020 31.Dt MINCORE 2 32.Os 33.Sh NAME 34.Nm mincore 35.Nd determine residency of memory pages 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In sys/mman.h 40.Ft int 41.Fn mincore "const void *addr" "size_t len" "char *vec" 42.Sh DESCRIPTION 43The 44.Fn mincore 45system call determines whether each of the pages in the region beginning at 46.Fa addr 47and continuing for 48.Fa len 49bytes is resident or mapped, depending on the value of sysctl 50.Va vm.mincore_mapped . 51.\"The beginning address, 52.\".Fa addr , 53.\"is first rounded down to a multiple of the page size (see 54.\".Xr getpagesize 3 ) . 55.\"The end address, 56.\".Fa addr No + Fa len , 57.\"is rounded up to a multiple of the page size. 58The status is returned in the 59.Fa vec 60array, one character per page. 61Each character is either 0 if the page is not resident, or a combination of 62the following flags (defined in 63.In sys/mman.h ) : 64.Bl -tag -width ".Dv MINCORE_REFERENCED_OTHER" 65.It Dv MINCORE_INCORE 66Page is in core (resident). 67.It Dv MINCORE_REFERENCED 68Page has been referenced by us. 69.It Dv MINCORE_MODIFIED 70Page has been modified by us. 71.It Dv MINCORE_REFERENCED_OTHER 72Page has been referenced. 73.It Dv MINCORE_MODIFIED_OTHER 74Page has been modified. 75.It Dv MINCORE_PSIND(i) 76Page is part of a large 77.Pq Dq super 78page with size given by index 79.Dv i 80in the array returned by 81.Xr getpagesizes 3 . 82.It Dv MINCORE_SUPER 83A mask of the valid 84.Dv MINCORE_PSIND() 85values. 86If any bits in this mask are set, the page is part of a large 87.Pq Dq super 88page. 89.El 90.Pp 91The information returned by 92.Fn mincore 93may be out of date by the time the system call returns. 94The only way to ensure that a page is resident is to lock it into memory 95with the 96.Xr mlock 2 97system call. 98.Pp 99If the 100.Va vm.mincore_mapped 101sysctl is set to a non-zero value (default), only the current process' 102mappings of the pages in the specified virtual address range are examined. 103This does not preclude the system from returning 104.Dv MINCORE_REFERENCED_OTHER 105and 106.Dv MINCORE_MODIFIED_OTHER 107statuses. 108Otherwise, if the sysctl value is zero, all resident pages backing the 109specified address range are examined, regardless of the mapping state. 110.Sh IMPLEMENTATION NOTES 111Prior to the introduction of 112.Dv MINCORE_PSIND() 113in 114.Fx 13.0 , 115.Dv MINCORE_SUPER 116consisted of a single bit equal to 117.Dv MINCORE_PSIND(1) . 118In particular, applications compiled using the old value of 119.Dv MINCORE_SUPER 120will not identify large pages with size index 2 as being large pages. 121.Sh RETURN VALUES 122.Rv -std mincore 123.Sh ERRORS 124The 125.Fn mincore 126system call will fail if: 127.Bl -tag -width Er 128.It Bq Er ENOMEM 129The virtual address range specified by the 130.Fa addr 131and 132.Fa len 133arguments is not fully mapped. 134.It Bq Er EFAULT 135The 136.Fa vec 137argument points to an illegal address. 138.El 139.Sh SEE ALSO 140.Xr madvise 2 , 141.Xr mlock 2 , 142.Xr mprotect 2 , 143.Xr msync 2 , 144.Xr munmap 2 , 145.Xr getpagesize 3 , 146.Xr getpagesizes 3 147.Sh HISTORY 148The 149.Fn mincore 150system call first appeared in 151.Bx 4.4 . 152