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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |
MIGRATE_PAGES(2) Linux Programmer's Manual MIGRATE_PAGES(2)
migrate_pages - move all pages in a process to another set of nodes
#include <numaif.h>
long migrate_pages(int pid, unsigned long maxnode,
const unsigned long *old_nodes,
const unsigned long *new_nodes);
Link with -lnuma.
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.
The migrate_pages() system call first appeared on Linux in version
2.6.16.
This system call is Linux-specific.
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 in the Linux kernel source tree
This page is part of release 4.12 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
Linux 2015-02-21 MIGRATE_PAGES(2)
Pages that refer to this page: swapon(2), syscalls(2), numa(3), numa_maps(5), capabilities(7), numa(7)