переместить все страницы в процессе в другой набор узлов (move all pages in a process to another set of nodes)
Имя (Name)
migrate_pages - move all pages in a process to another set of
nodes
Синопсис (Synopsis)
#include <numaif.h>
long migrate_pages(int pid, unsigned long maxnode,
const unsigned long *old_nodes,
const unsigned long *new_nodes);
Note: There is no glibc wrapper for this system call; see NOTES.
Link with -lnuma.
Описание (Description)
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.
Возвращаемое значение (Return value)
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.
Ошибки (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.
Версии (Versions)
The migrate_pages() system call first appeared on Linux in
version 2.6.16.
Стандарты (Conforming to)
This system call is Linux-specific.
Примечание (Note)
Glibc does not provide a wrapper for this system call. 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.
Смотри также (See also)
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
