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3 .\" Based on the move_pages manpage which was
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18 .TH MIGRATE_PAGES 2 2015-02-21 "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 );
30 Link with \fI\-lnuma\fP.
33 attempts to move all pages of the process
35 that are in memory nodes
37 to the memory nodes in
39 Pages not located in any node in
43 the kernel maintains the relative topology relationship inside
45 during the migration to
52 arguments are pointers to bit masks of node numbers, with up to
55 These masks are maintained as arrays of unsigned
59 integer, the bits beyond those specified by
64 argument is the maximum node number in the bit mask plus one (this is the same
72 argument is the ID of the process whose pages are to be moved.
73 To move pages in another process,
74 the caller must be privileged
76 or the real or effective user ID of the calling process must match the
77 real or saved-set user ID of the target process.
82 moves pages of the calling process.
84 Pages shared with another process will be moved only if the initiating
91 returns the number of pages that could not be moved
92 (i.e., a return of zero means that all pages were successfully moved).
93 On error, it returns \-1, and sets
95 to indicate the error.
99 Part or all of the memory range specified by
100 .IR old_nodes / new_nodes
103 points outside your accessible address space.
106 The value specified by
108 exceeds a kernel-imposed limit.
109 .\" As at 3.5, this limit is "a page worth of bits", e.g.,
110 .\" 8 * 4096 bits, assuming a 4kB page size.
115 specifies one or more node IDs that are
116 greater than the maximum supported node ID.
117 Or, none of the node IDs specified by
119 are on-line and allowed by the process's current cpuset context,
120 or none of the specified nodes contain memory.
123 Insufficient privilege
125 to move pages of the process specified by
127 or insufficient privilege
129 to access the specified target nodes.
135 .\" FIXME Document the other errors that can occur for migrate_pages()
139 system call first appeared on Linux in version 2.6.16.
141 This system call is Linux-specific.
143 For information on library support, see
147 .BR get_mempolicy (2)
149 .B MPOL_F_MEMS_ALLOWED
150 flag to obtain the set of nodes that are allowed by
151 the calling process's cpuset.
152 Note that this information is subject to change at any
153 time by manual or automatic reconfiguration of the cpuset.
157 may result in pages whose location
158 (node) violates the memory policy established for the
159 specified addresses (see
161 and/or the specified process (see
162 .BR set_mempolicy (2)).
163 That is, memory policy does not constrain the destination
165 .BR migrate_pages ().
169 header is not included with glibc, but requires installing
171 or a similar package.
173 .BR get_mempolicy (2),
175 .BR set_mempolicy (2),
180 .BR migratepages (8),
183 .IR Documentation/vm/page_migration
184 in the Linux kernel source tree