mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-01 08:27:59 +00:00
8269e7673c
Remove core system call implementations and documentation to lib/libsys and lib/libsys/<arch> from lib/libc/sys and lib/libc/<arch>/<sys>. Update paths to allow libc to find them in their new home. Reviewed by: kib, emaste, imp Pull Request: https://github.com/freebsd/freebsd-src/pull/908
150 lines
4.4 KiB
Groff
150 lines
4.4 KiB
Groff
.\" Copyright (c) 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.Dd August 23, 2020
|
|
.Dt MINCORE 2
|
|
.Os
|
|
.Sh NAME
|
|
.Nm mincore
|
|
.Nd determine residency of memory pages
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In sys/mman.h
|
|
.Ft int
|
|
.Fn mincore "const void *addr" "size_t len" "char *vec"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn mincore
|
|
system call determines whether each of the pages in the region beginning at
|
|
.Fa addr
|
|
and continuing for
|
|
.Fa len
|
|
bytes is resident or mapped, depending on the value of sysctl
|
|
.Va vm.mincore_mapped .
|
|
.\"The beginning address,
|
|
.\".Fa addr ,
|
|
.\"is first rounded down to a multiple of the page size (see
|
|
.\".Xr getpagesize 3 ) .
|
|
.\"The end address,
|
|
.\".Fa addr No + Fa len ,
|
|
.\"is rounded up to a multiple of the page size.
|
|
The status is returned in the
|
|
.Fa vec
|
|
array, one character per page.
|
|
Each character is either 0 if the page is not resident, or a combination of
|
|
the following flags (defined in
|
|
.In sys/mman.h ) :
|
|
.Bl -tag -width ".Dv MINCORE_REFERENCED_OTHER"
|
|
.It Dv MINCORE_INCORE
|
|
Page is in core (resident).
|
|
.It Dv MINCORE_REFERENCED
|
|
Page has been referenced by us.
|
|
.It Dv MINCORE_MODIFIED
|
|
Page has been modified by us.
|
|
.It Dv MINCORE_REFERENCED_OTHER
|
|
Page has been referenced.
|
|
.It Dv MINCORE_MODIFIED_OTHER
|
|
Page has been modified.
|
|
.It Dv MINCORE_PSIND(i)
|
|
Page is part of a large
|
|
.Pq Dq super
|
|
page with size given by index
|
|
.Dv i
|
|
in the array returned by
|
|
.Xr getpagesizes 3 .
|
|
.It Dv MINCORE_SUPER
|
|
A mask of the valid
|
|
.Dv MINCORE_PSIND()
|
|
values.
|
|
If any bits in this mask are set, the page is part of a large
|
|
.Pq Dq super
|
|
page.
|
|
.El
|
|
.Pp
|
|
The information returned by
|
|
.Fn mincore
|
|
may be out of date by the time the system call returns.
|
|
The only way to ensure that a page is resident is to lock it into memory
|
|
with the
|
|
.Xr mlock 2
|
|
system call.
|
|
.Pp
|
|
If the
|
|
.Va vm.mincore_mapped
|
|
sysctl is set to a non-zero value (default), only the current process'
|
|
mappings of the pages in the specified virtual address range are examined.
|
|
This does not preclude the system from returning
|
|
.Dv MINCORE_REFERENCED_OTHER
|
|
and
|
|
.Dv MINCORE_MODIFIED_OTHER
|
|
statuses.
|
|
Otherwise, if the sysctl value is zero, all resident pages backing the
|
|
specified address range are examined, regardless of the mapping state.
|
|
.Sh IMPLEMENTATION NOTES
|
|
Prior to the introduction of
|
|
.Dv MINCORE_PSIND()
|
|
in
|
|
.Fx 13.0 ,
|
|
.Dv MINCORE_SUPER
|
|
consisted of a single bit equal to
|
|
.Dv MINCORE_PSIND(1) .
|
|
In particular, applications compiled using the old value of
|
|
.Dv MINCORE_SUPER
|
|
will not identify large pages with size index 2 as being large pages.
|
|
.Sh RETURN VALUES
|
|
.Rv -std mincore
|
|
.Sh ERRORS
|
|
The
|
|
.Fn mincore
|
|
system call will fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er ENOMEM
|
|
The virtual address range specified by the
|
|
.Fa addr
|
|
and
|
|
.Fa len
|
|
arguments is not fully mapped.
|
|
.It Bq Er EFAULT
|
|
The
|
|
.Fa vec
|
|
argument points to an illegal address.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr madvise 2 ,
|
|
.Xr mlock 2 ,
|
|
.Xr mprotect 2 ,
|
|
.Xr msync 2 ,
|
|
.Xr munmap 2 ,
|
|
.Xr getpagesize 3 ,
|
|
.Xr getpagesizes 3
|
|
.Sh HISTORY
|
|
The
|
|
.Fn mincore
|
|
system call first appeared in
|
|
.Bx 4.4 .
|