VM_MAP_RAM(9) Memory Management in Linux VM_MAP_RAM(9)NAME
vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
void * vm_map_ram(struct page ** pages, unsigned int count, int node, pgprot_t prot);
an array of pointers to the pages to be mapped
number of pages
prefer to allocate data structures on this node
memory protection to use. PAGE_KERNEL for regular RAM
a pointer to the address that has been mapped, or NULL on failure
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 VM_MAP_RAM(9)
Check Out this Related Man Page
REMAP_FILE_PAGES(2) Linux Programmer's Manual REMAP_FILE_PAGES(2)NAME
remap_file_pages - create a nonlinear file mapping
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 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 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 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.
On success, remap_file_pages() returns 0. On error, -1 is returned, and errno is set appropriately.
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 version 2.3.3.
The remap_file_pages() system call is Linux-specific.
SEE ALSO getpagesize(2), mmap(2), mmap2(2), mprotect(2), mremap(2), msync(2), feature_test_macros(7)COLOPHON
This page is part of release 3.27 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)
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