REMAP_FILE_PAGES(2) Linux Programmer's Manual REMAP_FILE_PAGES(2)
remap_file_pages - create a nonlinear file mapping
#define _GNU_SOURCE /* See feature_test_macros(7) */
int remap_file_pages(void *addr, size_t size, int prot,
ssize_t pgoff, int flags);
The remap_file_pages() system call is used to create a nonlinear mapping, that is, a map-
ping 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)
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 cre-
ated with the MAP_SHARED flag.
2. Use one or more calls to 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.
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 mapping 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
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_NON-
BLOCK are ignored.
On success, remap_file_pages() returns 0. On error, -1 is returned, and errno is set
EINVAL addr does not refer to a valid mapping created with the MAP_SHARED flag.
EINVAL addr, size, prot, or pgoff is invalid.
The remap_file_pages() system call appeared in Linux 2.5.46; glibc support was added in
The remap_file_pages() system call is Linux-specific.
getpagesize(2), mmap(2), mmap2(2), mprotect(2), mremap(2), msync(2)
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Linux 2008-04-22 REMAP_FILE_PAGES(2)