migrate_pages(2)

1MIGRATE_PAGES(2)           Linux Programmer's Manual          MIGRATE_PAGES(2)
2
3
4

NAME

6       migrate_pages - move all pages in a process to another set of nodes
7

SYNOPSIS

9       #include <numaif.h>
10
11       long migrate_pages(int pid, unsigned long maxnode,
12                          const unsigned long * old_nodes,
13                          const unsigned long * new_nodes);
14
15       Link with -lnuma.
16

DESCRIPTION

18       migrate_pages()  moves  all pages of the process pid that are in memory
19       nodes old_nodes to the memory nodes in new_nodes.  Pages not located in
20       any  node  in  old_nodes will not be migrated.  As far as possible, the
21       kernel maintains the relative topology  relationship  inside  old_nodes
22       during the migration to new_nodes.
23
24       The old_nodes and new_nodes arguments are pointers to bit masks of node
25       numbers, with up to maxnode bits in each mask.  These masks  are  main‐
26       tained  as  arrays of unsigned long integers (in the last long integer,
27       the bits beyond those specified by maxnode are ignored).   The  maxnode
28       argument  is  the maximum node number in the bit mask plus one (this is
29       the same as in mbind(2), but different from select(2))
30
31       The pid argument is the ID of the process whose pages are to be  moved.
32       To  move  pages  in  another  process,  the  caller  must be privileged
33       (CAP_SYS_NICE) or the real or effective user ID of the calling  process
34       must match the real or saved-set user ID of the target process.  If pid
35       is 0, then migrate_pages() moves pages of the calling process.
36
37       Pages shared with another process will only be moved if the  initiating
38       process has the CAP_SYS_NICE privilege.
39

RETURN VALUE

41       On  success migrate_pages() returns zero.  On error, it returns -1, and
42       sets errno to indicate the error.
43

ERRORS

45       EPERM  Insufficient privilege  (CAP_SYS_NICE)  to  move  pages  of  the
46              process    specified   by   pid,   or   insufficient   privilege
47              (CAP_SYS_NICE) to access the specified target nodes.
48
49       ESRCH  No process matching pid could be found.
50

VERSIONS

52       The migrate_pages() system call first  appeared  on  Linux  in  version
53       2.6.16.
54

CONFORMING TO

56       This system call is Linux-specific.
57

NOTES

59       For information on library support, see numa(7).
60
61       Use  get_mempolicy(2)  with  the MPOL_F_MEMS_ALLOWED flag to obtain the
62       set of nodes that are allowed by the calling  process's  cpuset.   Note
63       that  this  information  is  subject to change at any time by manual or
64       automatic reconfiguration of the cpuset.
65
66       Use of migrate_pages() may result in pages whose location  (node)  vio‐
67       lates  the  memory  policy established for the specified addresses (see
68       mbind(2)) and/or the specified process  (see  set_mempolicy(2)).   That
69       is,  memory  policy  does  not  constrain the destination nodes used by
70       migrate_pages().
71
72       The  <numaif.h>  header  is  not  included  with  glibc,  but  requires
73       installing libnuma-devel or a similar package.
74

COLOPHON

80       This page is part of release 3.25 of the Linux  man-pages  project.   A
81       description  of  the project, and information about reporting bugs, can
82       be found at http://www.kernel.org/doc/man-pages/.
83
84
85
86Linux                             2010-06-11                  MIGRATE_PAGES(2)