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NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | STANDARDS | HISTORY | NOTES | SEE ALSO | COLOPHON |
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migrate_pages(2) System Calls Manual migrate_pages(2)
migrate_pages - move all pages in a process to another set of
nodes
NUMA (Non-Uniform Memory Access) policy library (libnuma, -lnuma)
#include <numaif.h>
long migrate_pages(int pid, unsigned long maxnode,
const unsigned long *old_nodes,
const unsigned long *new_nodes);
migrate_pages() attempts to move all pages of the process pid that
are in memory nodes old_nodes to the memory nodes in new_nodes.
Pages not located in any node in old_nodes will not be migrated.
As far as possible, the kernel maintains the relative topology
relationship inside old_nodes during the migration to new_nodes.
The old_nodes and new_nodes arguments are pointers to bit masks of
node numbers, with up to maxnode bits in each mask. These masks
are maintained as arrays of unsigned long integers (in the last
long integer, the bits beyond those specified by maxnode are
ignored). The maxnode argument is the maximum node number in the
bit mask plus one (this is the same as in mbind(2), but different
from select(2)).
The pid argument is the ID of the process whose pages are to be
moved. To move pages in another process, the caller must be
privileged (CAP_SYS_NICE) or the real or effective user ID of the
calling process must match the real or saved-set user ID of the
target process. If pid is 0, then migrate_pages() moves pages of
the calling process.
Pages shared with another process will be moved only if the
initiating process has the CAP_SYS_NICE privilege.
On success migrate_pages() returns the number of pages that could
not be moved (i.e., a return of zero means that all pages were
successfully moved). On error, it returns -1, and sets errno to
indicate the error.
EFAULT Part or all of the memory range specified by
old_nodes/new_nodes and maxnode points outside your
accessible address space.
EINVAL The value specified by maxnode exceeds a kernel-imposed
limit. Or, old_nodes or new_nodes specifies one or more
node IDs that are greater than the maximum supported node
ID. Or, none of the node IDs specified by new_nodes are
on-line and allowed by the process's current cpuset
context, or none of the specified nodes contain memory.
EPERM Insufficient privilege (CAP_SYS_NICE) to move pages of the
process specified by pid, or insufficient privilege
(CAP_SYS_NICE) to access the specified target nodes.
ESRCH No process matching pid could be found.
Linux.
Linux 2.6.16.
For information on library support, see numa(7).
Use get_mempolicy(2) with the MPOL_F_MEMS_ALLOWED flag to obtain
the set of nodes that are allowed by the calling process's cpuset.
Note that this information is subject to change at any time by
manual or automatic reconfiguration of the cpuset.
Use of migrate_pages() may result in pages whose location (node)
violates the memory policy established for the specified addresses
(see mbind(2)) and/or the specified process (see
set_mempolicy(2)). That is, memory policy does not constrain the
destination nodes used by migrate_pages().
The <numaif.h> header is not included with glibc, but requires
installing libnuma-devel or a similar package.
get_mempolicy(2), mbind(2), set_mempolicy(2), numa(3),
numa_maps(5), cpuset(7), numa(7), migratepages(8), numastat(8)
Documentation/vm/page_migration.rst in the Linux kernel source
tree
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.15.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2025-08-11. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.15 2025-05-17 migrate_pages(2)
Pages that refer to this page: swapon(2), syscalls(2), numa(3), capabilities(7), numa(7)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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