MOVE_PAGES(2) Linux System Calls MOVE_PAGES(2)NAMEmove_pages - move a set of pages of a process to a different NUMA node
SYNOPSIS
#include <syscall.h>
long move_pages(pid_t pid, unsigned long nr_pages,
const void **address,
const int *nodes, int *status,
int flags);
DESCRIPTIONmove_pages moves a set of pages in the address space of a executed
process to a different NUMA node. The function can also be used to
determine the nodes to which the pages are currently mapped.
pid is the process whose pages will be moved. The value 0 specifies
the current process.
The argument nr_pages specifies the number of pages which would require
moving.
addresses is an array of addresses of pages which would require moving
nodes is an array of numbers of nodes to move the corresponding pages
to. If set to NULL, status is filled with current NUMA node IDs, but
no migrations occur.
The flags argument describes the type of pages which will be moved:
MPOL_MF_MOVE
Syscall will move only pages which are mapped only by the
process pid.
MPOL_MF_MOVE_ALL
Syscall will move pages which are mapped by multiple processes
too (this mode needs to have sufficient permissions).
The status field is only valid if move_pages finished successfully.
This field contains the status of the specified pages. If the nodes
argument is NULL or the migration succeeded, it is set to the node ID.
Otherwise it contains a negative number, one of the following error
codes:
-EFAULT the specified address does not point to a valid mapping
-ENOENT the page does not exist
-EPERM the page can't be moved (it is mlocked)
-EACCES the page is shared by multiple processes and the flag
MPOL_MF_MOVE_ALL was not set
-EBUSY the page could not be moved - it is busy now
-EFAULT the page address is not valid
-ENOMEM insufficient memory
-EIO the page can't be written
-EINVAL the page can't be moved because the file system does not imple‐
ment the necessary interface
RETURN VALUE
If nodes is not NULL, move_pages returns the number of valid migration
requests which could not currently be performed. Otherwise it returns
0.
An error indication is returned on error.
ERRORS
EACCES one of the nodes specified by the nodes argument is not allowed
for the specified process.
EINVAL the man pages to be moved are in kernel thread or the flag
parameter is invalid.
ENODEV one of the nodes specified by the nodes argument is not avail‐
able.
ENOENT there is no page which would be moved.
EPERM the flag is set to MPOL_MF_MOVE_ALL or pid doesn't specify the
current process, and the process has insufficient privileges.
ENOMEM insufficient memory
E2BIG the number of pages to move is too big
ESRCH the process pid can't be found
AVAILABILITY
This syscall is implemented only on the i386 and IA-64 architectures
since kernel 2.6.
Linux 8 August 2006 MOVE_PAGES(2)
