migratepages

MIGRATEPAGES(8)          Linux Administrator's Manual          MIGRATEPAGES(8)



NAME
       migratepages - Migrate the physical location a processes pages

SYNOPSIS
       migratepages pid from-nodes to-nodes

DESCRIPTION
       migratepages moves the physical location of a processes pages without
       any changes of the virtual address space of the process. Moving the
       pages allows one to change the distances of a process to its memory.
       Performance may be optimized by moving a processes pages to the node
       where it is executing.

       If multiple nodes are specified for from-nodes or to-nodes then an
       attempt is made to preserve the relative location of each page in each
       nodeset.

       For example if we move from nodes 2-5 to 7,9,12-13 then the preferred
       mode of operation is to move pages from 2->7, 3->9, 4->12 and 5->13.
       However, this is only posssible if enough memory is available.

       Valid node specifiers

              all                 All nodes
              number              Node number
              number1{,number2}   Node number1 and Node number2
              number1-number2     Nodes from number1 to number2
              ! nodes             Invert selection of the following specification.

NOTES
       Requires an NUMA policy aware kernel with support for page migration
       (linux 2.6.16 and later).

       migratepages will only move pages that are not shared with other
       processes if called by a user without administrative priviledges (but
       with the right to modify the process).

       migratepages will move all pages if invoked from root (or a user with
       administrative priviledges).


FILES
       /proc/<pid>/numa_maps for information about the NUMA memory use of a
       process.

COPYRIGHT
       Copyright 2005-2006 Christoph Lameter, Silicon Graphics, Inc.
       migratepages is under the GNU General Public License, v.2


SEE ALSO
       numactl(8) , set_mempolicy(2) , get_mempolicy(2) , mbind(2) ,
       sched_setaffinity(2) , sched_getaffinity(2) , proc(5) , ftok(3) ,
       shmat(2) , taskset(1)




SGI                                Jan 2005                    MIGRATEPAGES(8)