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Diffstat (limited to 'man2/remap_file_pages.2')
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diff --git a/man2/remap_file_pages.2 b/man2/remap_file_pages.2 deleted file mode 100644 index 0c87352c0..000000000 --- a/man2/remap_file_pages.2 +++ /dev/null @@ -1,170 +0,0 @@ -.\" Copyright (C) 2003, Michael Kerrisk <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.\" 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 (date) "Linux man-pages (unreleased)" -.SH NAME -remap_file_pages \- create a nonlinear file mapping -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" -.B #include <sys/mman.h> -.P -.BI "[[deprecated]] int remap_file_pages(void " addr [. size "], size_t " size , -.BI " int " prot ", size_t " pgoff ", \ -int " flags ); -.fi -.SH DESCRIPTION -.BR Note : -.\" commit 33041a0d76d3c3e0aff28ac95a2ffdedf1282dbc -.\" http://lwn.net/Articles/597632/ -this system call was marked as deprecated starting with Linux 3.16. -In Linux 4.0, the implementation was replaced -.\" commit c8d78c1823f46519473949d33f0d1d33fe21ea16 -by a slower in-kernel emulation. -Those few applications that use this system call should -consider migrating to alternatives. -This change was made because the kernel code for this system call was complex, -and it is believed to be little used or perhaps even completely unused. -While it had some use cases in database applications on 32-bit systems, -those use cases don't exist on 64-bit systems. -.P -The -.BR remap_file_pages () -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 () -over using repeated calls to -.BR mmap (2) -is that the former approach does not require the kernel to create -additional VMA (Virtual Memory Area) data structures. -.P -To create a nonlinear mapping we perform the following steps: -.TP 3 -1. -Use -.BR mmap (2) -to create a mapping (which is initially linear). -This mapping must be created with the -.B MAP_SHARED -flag. -.TP -2. -Use one or more calls to -.BR remap_file_pages () -to rearrange the correspondence between the pages of the mapping -and the pages of the file. -It is possible to map the same page of a file -into multiple locations within the mapped region. -.P -The -.I pgoff -and -.I size -arguments specify the region of the file that is to be relocated -within the mapping: -.I pgoff -is a file offset in units of the system page size; -.I size -is the length of the region in bytes. -.P -The -.I addr -argument serves two purposes. -First, it identifies the mapping whose pages we want to rearrange. -Thus, -.I addr -must be an address that falls within -a region previously mapped by a call to -.BR mmap (2). -Second, -.I addr -specifies the address at which the file pages -identified by -.I pgoff -and -.I size -will be placed. -.P -The values specified in -.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 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(). -.\" MTK, 14 Sep 2005 -.P -The -.I prot -argument must be specified as 0. -.P -The -.I flags -argument has the same meaning as for -.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 to indicate the error. -.SH ERRORS -.TP -.B EINVAL -.I addr -does not refer to a valid mapping -created with the -.B MAP_SHARED -flag. -.TP -.B EINVAL -.IR addr , -.IR size , -.IR prot , -or -.I pgoff -is invalid. -.\" And possibly others from vma->vm_ops->populate() -.SH STANDARDS -Linux. -.SH HISTORY -Linux 2.5.46, -glibc 2.3.3. -.SH NOTES -Since Linux 2.6.23, -.\" commit 3ee6dafc677a68e461a7ddafc94a580ebab80735 -.BR remap_file_pages () -creates non-linear mappings only -on in-memory filesystems such as -.BR tmpfs (5), -hugetlbfs or ramfs. -On filesystems with a backing store, -.BR remap_file_pages () -is not much more efficient than using -.BR mmap (2) -to adjust which parts of the file are mapped to which addresses. -.SH SEE ALSO -.BR getpagesize (2), -.BR mmap (2), -.BR mmap2 (2), -.BR mprotect (2), -.BR mremap (2), -.BR msync (2) |