remap_file_pages man page on Hurd

Man page or keyword search:  
man Server   6387 pages
apropos Keyword Search (all sections)
Output format
Hurd logo
[printable version]

REMAP_FILE_PAGES(2)	   Linux Programmer's Manual	   REMAP_FILE_PAGES(2)

NAME
       remap_file_pages - create a nonlinear file mapping

SYNOPSIS
       #define _GNU_SOURCE	   /* See feature_test_macros(7) */
       #include <sys/mman.h>

       int remap_file_pages(void *addr, size_t size, int prot,
			    ssize_t pgoff, int flags);

DESCRIPTION
       The  remap_file_pages()	system call is used to create a nonlinear map‐
       ping, that is, a mapping in which the pages of the file are mapped into
       a   nonsequential   order   in	memory.	   The	 advantage   of	 using
       remap_file_pages() over using repeated calls to	mmap(2)	 is  that  the
       former  approach	 does  not require the kernel to create additional VMA
       (Virtual Memory Area) data structures.

       To create a nonlinear mapping we perform the following steps:

       1. Use mmap(2) to create a mapping (which is initially  linear).	  This
	  mapping must be created with the MAP_SHARED flag.

       2. Use  one or more calls to remap_file_pages() to rearrange the corre‐
	  spondence 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.

       The pgoff and size arguments specify the region of the file that is  to
       be relocated within the mapping: pgoff is a file offset in units of the
       system page size; size is the length of the region in bytes.

       The addr argument serves two purposes.  First, it identifies  the  map‐
       ping  whose  pages we want to rearrange.	 Thus, addr must be an address
       that falls within a region previously mapped  by	 a  call  to  mmap(2).
       Second,	addr  specifies the address at which the file pages identified
       by pgoff and size will be placed.

       The values specified in addr and size should be multiples of the system
       page size.  If they are not, then the kernel rounds both values down to
       the nearest multiple of the page size.

       The prot argument must be specified as 0.

       The flags argument has the same meaning as for mmap(2), but  all	 flags
       other than MAP_NONBLOCK are ignored.

RETURN VALUE
       On  success,  remap_file_pages()	 returns 0.  On error, -1 is returned,
       and errno is set appropriately.

ERRORS
       EINVAL addr does	 not  refer  to	 a  valid  mapping  created  with  the
	      MAP_SHARED flag.

       EINVAL addr, size, prot, or pgoff is invalid.

VERSIONS
       The remap_file_pages() system call appeared in Linux 2.5.46; glibc sup‐
       port was added in version 2.3.3.

CONFORMING TO
       The remap_file_pages() system call is Linux-specific.

SEE ALSO
       getpagesize(2), mmap(2), mmap2(2), mprotect(2), mremap(2), msync(2)

COLOPHON
       This page is part of release 3.55 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux				  2008-04-22		   REMAP_FILE_PAGES(2)
[top]

List of man pages available for Hurd

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net