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 placement 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.

       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 + notation, specify !+N-N. When same is specified the pre-
       vious nodemask specified on the command line is used.  all means all nodes in the current cpuset.

       Instead of a number a node can also be:

       netdev:DEV		  The node connected to network device DEV.
       file:PATH		  The node the block device of PATH.
       ip:HOST			  The node of the network device of HOST
       block:PATH		  The node of block device PATH
       pci:[seg:]bus:dev[:func]   The node of a PCI device.

       Note that block resolves the kernel block device names only for udev names in /dev use file:

       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 --cpunodebind.

       --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 spec-
	      ified 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
	      Always allocate on the current node.

       --preferred=node
	      Preferably allocate memory on node, but if memory cannot be allocated there fall back to other nodes.  This option takes only a sin-
	      gle 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 segment 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 --cpunodebind=0 --membind=0,1 process Run process on node 0 with memory allocated on node 0 and 1.

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

       numactl --nodebind=netdev:eth0 --membind=netdev:eth0 network-server Run network-server on the node of network device eth0 with  its  memory
       also in the same node.

       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.

       Place a tmpfs file on 2 nodes:
	 numactl --membind=2 dd if=/dev/zero of=/dev/shm/A bs=1M count=1024
	 numactl --membind=3 dd if=/dev/zero of=/dev/shm/A seek=1024 bs=1M count=1024

       numactl --localalloc /dev/shm/file Reset the policy for the shared memory 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 deprecated 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 programs 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)