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



NAME
       numactl - Control NUMA policy for processes or shared memory

SYNOPSIS
       numactl [ --interleave nodes ] [ --preferred node ] [ --membind nodes ]
       [ --cpunodebind nodes ] [ --physcpubind cpus ] [	 --localalloc  ]  [--]
       command {arguments ...}
       numactl --show
       numactl --hardware
       numactl [ --huge ] [ --offset offset ] [ --shmmode shmmode ] [ --length
       length ] [ --strict ]
       [ --shmid id ] --shm shmkeyfile | --file tmpfsfile
       [ --touch ] [ --dump ] [ --dump-nodes ] memory policy

DESCRIPTION
       numactl runs processes with a specific NUMA scheduling or memory place-
       ment policy.  The policy is set for command and inherited by all of its
       children.  In addition it can set persistent policy for	shared	memory
       segments or files.

       Use -- before command if using command options that could be confused
	      with numactl options.

       Policy settings are:

       --interleave=nodes, -i nodes
	      Set  a  memory interleave policy. Memory will be allocated using
	      round robin on nodes.  When memory cannot be  allocated  on  the
	      current  interleave  target  fall back to other nodes.  Multiple
	      nodes may be specified on --interleave, --membind and --cpunode-
	      bind.   You may specify "all", which means all nodes in the cur-
	      rent cpuset.  nodes may be specified as N,N,N or	N-N  or	 N,N-N
	      or   N-N,N-N  and	 so  forth.  Relative nodes may be specifed as
	      +N,N,N or	 +N-N or +N,N-N and so forth. The + indicates that the
	      node  numbers  are relative to the process' set of allowed nodes
	      in its current cpuset.  A !N-N notation indicates the inverse of
	      N-N,  in other words all nodes except N-N.  If used with + nota-
	      tion, specify !+N-N.

       --membind=nodes, -m nodes
	      Only allocate memory from	 nodes.	  Allocation  will  fail  when
	      there  is not enough memory available on these nodes.  nodes may
	      be specified as noted above.

       --cpunodebind=nodes, -N nodes
	      Only execute command on the CPUs of nodes.  Note that nodes  may
	      consist  of  multiple  CPUs.   nodes  may	 be specified as noted
	      above.

       --physcpubind=cpus, -C cpus
	      Only execute process on cpus.  This accepts cpu numbers as shown
	      in the processor fields of /proc/cpuinfo, or relative cpus as in
	      relative to the current cpuset.  You may	specify	 "all",	 which
	      means  all  cpus	in  the	 current cpuset.  Physical cpus may be
	      specified as N,N,N or  N-N or N,N-N or  N-N,N-N  and  so	forth.
	      Relative	cpus  may be specifed as +N,N,N or  +N-N or +N,N-N and
	      so forth. The + indicates that the cpu numbers are  relative  to
	      the  process' set of allowed cpus in its current cpuset.	A !N-N
	      notation indicates the inverse of N-N, in other words  all  cpus
	      except N-N.  If used with + notation, specify !+N-N.

       --localalloc, -l
	      Falls  back  to  the system default which is local allocation by
	      using MPOL_DEFAULT policy. See mbind(2) for details.

       --preferred=node
	      Preferably allocate memory on node,  but	if  memory  cannot  be
	      allocated	 there	fall  back  to other nodes.  This option takes
	      only a single node number.  Relative notation may be used.

       --show, -s
	      Show NUMA policy settings of the current process.

       --hardware, -H
	      Show inventory of available nodes on the system.

       Numactl can set up policy for a SYSV shared memory segment or a file in
       shmfs/hugetlbfs.

       This  policy  is	 persistent and will be used by all mappings from that
       shared memory. The order of options matters  here.   The	 specification
       must  at	 least include either of --shm, --shmid, --file to specify the
       shared memory segment or file and a memory policy like described	 above
       ( --interleave, --localalloc, --preferred, --membind ).

       --huge
       When  creating a SYSV shared memory segment use huge pages.  Only valid
       before --shmid or --shm

       --offset
       Specify offset into the shared memory segment. Default 0.  Valid	 units
       are m (for MB), g (for GB), k (for KB), otherwise it specifies bytes.

       --strict
       Give  an	 error	when  a page in the policied area in the shared memory
       segment already was faulted in with a conflicting policy. Default is to
       silently ignore this.

       --shmmode shmmode
       Only  valid  before --shmid or --shm When creating a shared memory seg-
       ment set it to numeric mode shmmode.

       --length length
       Apply policy to length range in the shared memory segment or  make  the
       segment	length	long  Default  is to use the remaining length Required
       when a shared memory segment is created and specifies the length of the
       new  segment  then. Valid units are m (for MB), g (for GB), k (for KB),
       otherwise it specifies bytes.

       --shmid id
       Create or use an shared memory segment with numeric ID id

       --shm shmkeyfile
       Create or use an shared memory segment, with  the  ID  generated	 using
       ftok(3) from shmkeyfile

       --file tmpfsfile
       Set policy for a file in tmpfs or hugetlbfs

       --touch
       Touch  pages to enforce policy early. Default is to not touch them, the
       policy is applied when an applications maps and accesses a page.

       --dump
       Dump policy in the specified range.

       --dump-nodes
       Dump all nodes of the specific range (very verbose!)

       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.

EXAMPLES
       numactl --physcpubind=+0-4,8-12 myapplic arguments Run myapplic on cpus
       0-4 and 8-12 of the current cpuset.

       numactl	--interleave=all  bigdatabase  arguments Run big database with
       its memory interleaved on all CPUs.

       numactl --cpubind=0 --membind=0,1 process Run process on	 node  0  with
       memory allocated on node 0 and 1.

       numactl	--cpubind=0  --membind=0,1 -- process -l Run process as above,
       but with an option (-l) that would be confused with a numactl option.

       numactl --preferred=1 numactl --show Set preferred node 1 and show  the
       resulting state.

       numactl --interleave=all --shmkeyfile /tmp/shmkey Interleave all of the
       sysv shared memory region specified by /tmp/shmkey over all nodes.

       numactl --offset=1G --length=1G --membind=1 --file  /dev/shm/A  --touch
       Bind the second gigabyte in the tmpfs file /dev/shm/A to node 1.

       numactl --localalloc /dev/shm/file Reset the policy for the shared mem-
       ory file file to the default localalloc policy.

NOTES
       Requires an NUMA policy aware kernel.

       Command is not executed using  a	 shell.	 If  you  want	to  use	 shell
       metacharacters in the child use sh -c as wrapper.

       Setting	policy for a hugetlbfs file does currently not work because it
       cannot be extended by truncate.

       Shared memory segments larger than numactl's address  space  cannot  be
       completely  policied.  This  could be a problem on 32bit architectures.
       Changing it piece by piece may work.

       The old --cpubind which accepts node numbers, not cpu numbers, is  dep-
       recated	and  replaced  with  the  new  --cpunodebind and --physcpubind
       options.


FILES
       /proc/cpuinfo for the listing of active CPUs. See proc(5) for details.

       /sys/devices/system/node/node*/numastat for NUMA memory hit statistics.


COPYRIGHT
       Copyright 2002,2004 Andi Kleen, SuSE Labs.  numactl and the  demo  pro-
       grams are under the GNU General Public License, v.2


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




SuSE Labs			   Mar 2004			    NUMACTL(8)