-.\" Copyright (C) 2003, Michael Kerrisk (mtk-manpages@gmx.net)
+.\" Copyright (C) 2003, Michael Kerrisk (mtk.manpages@gmail.com)
.\"
+.\" %%%LICENSE_START(VERBATIM)
.\" 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.
.\" 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.\" manual page may be incorrect or out-of-date.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 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
+.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
.\"
-.\" 2003-12-10 Initial creation, Michael Kerrisk <mtk-manpages@gmx.net>
+.\" 2003-12-10 Initial creation, Michael Kerrisk <mtk.manpages@gmail.com>
.\" 2004-10-28 aeb, corrected prototype, prot must be 0
.\"
-.TH REMAP_FILE_PAGES 2 2004-10-28 "Linux 2.6" "Linux Programmer's Manual"
+.TH REMAP_FILE_PAGES 2 2008-04-22 "Linux" "Linux Programmer's Manual"
.SH NAME
-remap_file_pages \- create a non-linear file mapping
+remap_file_pages \- create a nonlinear file mapping
.SH SYNOPSIS
+.nf
+.BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */"
.B #include <sys/mman.h>
.sp
-.BI "int remap_file_pages(void *" start ", "
-.BI "size_t " size ", int " prot ", "
-.BI "ssize_t " pgoff ", int " flags );
+.BI "int remap_file_pages(void *" addr ", size_t " size ", int " prot ,
+.BI " ssize_t " pgoff ", int " flags );
+.fi
.SH DESCRIPTION
The
.BR remap_file_pages ()
-system call is used to create a non-linear mapping, that is, a mapping
-in which the pages of the file are mapped into a non-sequential order
+system call is used to create a nonlinear mapping, that is, a mapping
+in which the pages of the file are mapped into a nonsequential order
in memory.
The advantage of using
.BR remap_file_pages ()
is that the former approach does not require the kernel to create
additional VMA (Virtual Memory Area) data structures.
-To create a non-linear mapping we perform the following steps:
-.TP
-\fB1.\fP
+To create a nonlinear mapping we perform the following steps:
+.TP 3
+1.
Use
-.BR mmap ()
+.BR mmap (2)
to create a mapping (which is initially linear).
This mapping must be created with the
-MAP_SHARED flag.
+.B MAP_SHARED
+flag.
.TP
-\fB2.\fP
+2.
Use one or more calls to
.BR remap_file_pages ()
to rearrange the correspondence between the pages of the mapping
is the length of the region in bytes.
The
-.I start
+.I addr
argument serves two purposes.
First, it identifies the mapping whose pages we want to rearrange.
Thus,
-.I start
+.I addr
must be an address that falls within
a region previously mapped by a call to
-.BR mmap ().
+.BR mmap (2).
Second,
-.I start
+.I addr
specifies the address at which the file pages
identified by
.I pgoff
will be placed.
The values specified in
-.I start
+.I addr
and
.I size
should be multiples of the system page size.
If they are not, then the kernel rounds
-.I both
-values
+.I both
+values
.I down
to the nearest multiple of the page size.
-.\" This rounding is weird, and not consistent with the treatment of
-.\" the analogous arguments for munmap()/mprotect() and for mlock().
+.\" This rounding is weird, and not consistent with the treatment of
+.\" the analogous arguments for munmap()/mprotect() and for mlock().
.\" MTK, 14 Sep 2005
The
The
.I flags
argument has the same meaning as for
-.BR mmap (),
-but all flags other than MAP_NONBLOCK are ignored.
-.SH "RETURN VALUE"
+.BR mmap (2),
+but all flags other than
+.B MAP_NONBLOCK
+are ignored.
+.SH RETURN VALUE
On success,
.BR remap_file_pages ()
returns 0.
On error, \-1 is returned, and
.I errno
is set appropriately.
-.SH NOTES
-The
-.BR remap_file_pages ()
-system call appeared in Linux 2.5.46.
.SH ERRORS
.TP
.B EINVAL
-.I start
+.I addr
does not refer to a valid mapping
-created with the MAP_SHARED flag.
+created with the
+.B MAP_SHARED
+flag.
.TP
.B EINVAL
-.IR start ,
+.IR addr ,
.IR size ,
.IR prot ,
or
.I pgoff
is invalid.
.\" And possibly others from vma->vm_ops->populate()
-.SH "CONFORMING TO"
+.SH VERSIONS
+The
+.BR remap_file_pages ()
+system call appeared in Linux 2.5.46;
+glibc support was added in version 2.3.3.
+.SH CONFORMING TO
The
.BR remap_file_pages ()
-system call is Linux specific.
-.SH "SEE ALSO"
+system call is Linux-specific.
+.SH SEE ALSO
.BR getpagesize (2),
.BR mmap (2),
.BR mmap2 (2),
projects / thirdparty / man-pages.git / blobdiff