1.\" $NetBSD: mincore.2,v 1.21 2022/07/26 00:25:45 uwe Exp $ 2.\" 3.\" Copyright (c) 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)mincore.2 8.1 (Berkeley) 6/9/93 31.\" 32.Dd June 6, 1999 33.Dt MINCORE 2 34.Os 35.Sh NAME 36.Nm mincore 37.Nd determine residency of memory pages 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In sys/mman.h 42.Ft int 43.Fn mincore "void *addr" "size_t len" "char *vec" 44.Sh DESCRIPTION 45The 46.Fn mincore 47system call tells whether the pages covering 48.Fa len 49bytes of data starting at 50.Fa addr 51are core resident in the process. 52The status of the memory range is returned in the character-per-page array 53.Fa vec . 54If the page is resident, the least significant bit of the corresponding 55character in 56.Fa vec 57will be set. 58Other bits are reserved for additional information 59which future implementations may return. 60.Pp 61Note that the status of each page may change between the call to 62.Fn mincore 63and the return of the page status information. 64In order to guarantee 65that pages will remain in core, the address range must be locked with 66.Xr mlock 2 . 67.Sh RETURN VALUES 68.Rv -std mincore 69.Sh ERRORS 70The 71.Fn mincore 72call will fail if: 73.Bl -tag -width Er 74.It Bq Er EFAULT 75.Fa vec 76points to an illegal address. 77.It Bq Er EINVAL 78.Fa addr 79is not a multiple of the system page size. 80.It Bq Er EINVAL 81.Fa len 82is equal to 0. 83.It Bq Er ENOMEM 84The address range specified is invalid for the calling process, 85or one or more of the pages specified in the range are not mapped. 86.El 87.Sh SEE ALSO 88.Xr madvise 2 , 89.Xr mlock 2 , 90.Xr mprotect 2 , 91.Xr msync 2 , 92.Xr munmap 2 , 93.Xr sysconf 3 94.Sh HISTORY 95The 96.Fn mincore 97function first appeared in 98.Bx 4.4 . 99