• NAME
  
  move_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 );                                                                 
  
  
  

• DESCRIPTION
  
  move_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 implement 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 available.
  
  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.
  

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