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.

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