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3 .\" Based on the move_pages manpage which was
4 .\" This manpage is Copyright (C) 2006 Silicon Graphics, Inc.
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18 .TH MIGRATE_PAGES 2 2021-03-22 "Linux" "Linux Programmer's Manual"
20 migrate_pages \- move all pages in a process to another set of nodes
23 .B #include <numaif.h>
25 .BI "long migrate_pages(int " pid ", unsigned long " maxnode,
26 .BI " const unsigned long *" old_nodes,
27 .BI " const unsigned long *" new_nodes );
31 There is no glibc wrapper for this system call; see NOTES.
33 Link with \fI\-lnuma\fP.
36 attempts to move all pages of the process
38 that are in memory nodes
40 to the memory nodes in
42 Pages not located in any node in
46 the kernel maintains the relative topology relationship inside
48 during the migration to
55 arguments are pointers to bit masks of node numbers, with up to
58 These masks are maintained as arrays of unsigned
62 integer, the bits beyond those specified by
67 argument is the maximum node number in the bit mask plus one (this is the same
75 argument is the ID of the process whose pages are to be moved.
76 To move pages in another process,
77 the caller must be privileged
79 or the real or effective user ID of the calling process must match the
80 real or saved-set user ID of the target process.
85 moves pages of the calling process.
87 Pages shared with another process will be moved only if the initiating
94 returns the number of pages that could not be moved
95 (i.e., a return of zero means that all pages were successfully moved).
96 On error, it returns \-1, and sets
98 to indicate the error.
102 Part or all of the memory range specified by
103 .IR old_nodes / new_nodes
106 points outside your accessible address space.
109 The value specified by
111 exceeds a kernel-imposed limit.
112 .\" As at 3.5, this limit is "a page worth of bits", e.g.,
113 .\" 8 * 4096 bits, assuming a 4kB page size.
118 specifies one or more node IDs that are
119 greater than the maximum supported node ID.
120 Or, none of the node IDs specified by
122 are on-line and allowed by the process's current cpuset context,
123 or none of the specified nodes contain memory.
126 Insufficient privilege
128 to move pages of the process specified by
130 or insufficient privilege
132 to access the specified target nodes.
138 .\" FIXME Document the other errors that can occur for migrate_pages()
142 system call first appeared on Linux in version 2.6.16.
144 This system call is Linux-specific.
146 Glibc does not provide a wrapper for this system call.
147 For information on library support, see
151 .BR get_mempolicy (2)
153 .B MPOL_F_MEMS_ALLOWED
154 flag to obtain the set of nodes that are allowed by
155 the calling process's cpuset.
156 Note that this information is subject to change at any
157 time by manual or automatic reconfiguration of the cpuset.
161 may result in pages whose location
162 (node) violates the memory policy established for the
163 specified addresses (see
165 and/or the specified process (see
166 .BR set_mempolicy (2)).
167 That is, memory policy does not constrain the destination
169 .BR migrate_pages ().
173 header is not included with glibc, but requires installing
175 or a similar package.
177 .BR get_mempolicy (2),
179 .BR set_mempolicy (2),
184 .BR migratepages (8),
187 .IR Documentation/vm/page_migration.rst
188 in the Linux kernel source tree