numactl \- Control NUMA policy for processes or shared memory

.B numactl

[

.B \-\-interleave nodes

] [

.B \-\-preferred node

] [

.B \-\-membind nodes

] [

.B \-\-cpubind nodes

] [

.B \-\-localalloc

] command {arguments ...}

.br

.B numactl \-\-show

.br

.B numactl \-\-hardware

.br

.B numactl

[

.B \-\-huge

] [

.B \-\-offset offset

] [

.B \-\-mode shmmode

] [

.B \-\-length length

] [

.B \-\-strict

]

.br

.B \-\-shmid id

|

.B \-\-shm shmkeyfile

|

.B \-\-file tmpfsfile

.br

[

.B \-\-touch

] [

.B \-\-dump

]

memory policy

.B 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.

.TP

.TP

Set an memory interleave policy. Memory will be allocated using round robin

on

.I nodes.

When memory cannot be allocated on the current interleave target fall back

to other nodes.

.TP

Only allocate memory from nodes. Allocation will fail when there

is not enough memory available on these nodes.

.TP

Only execute process on the CPUs of

.I nodes.

.TP

Do always local allocation on the current node.

.TP

Preferably allocate memory on

.I node,

but if memory cannot be allocated there fall back to other nodes.

This option takes only a single node number.

.TP

Show NUMA policy settings of the current process.

.TP

Show inventory of available nodes on the system.

.TP 0

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

.I \-\-shm,

.I \-\-shmid,

.I \-\-file

to specify the shared memory segment or file and a memory policy like described

above (

.I \-\-interleave,

.I \-\-localalloc,

.I \-\-prefered,

.I \-\-membind

).

.TP

When creating a SYSV shared memory segment use huge pages.

Only valid before \-\-shmid or \-\-shm

.TP

Specify offset into the shared memory segment. Default 0.

Valid units are

.I m

(for MB),

.I g

(for GB),

.I k

(for KB),

otherwise it specifies bytes.

.TP

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.

.TP

Only valid before \-\-shmid or \-\-shm

When creating a shared memory segment set it to numeric mode

.I shmmode.

.TP

Apply policy to

.I 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

.I m

(for MB),

.I g

(for GB),

.I k

(for KB),

otherwise it specifies bytes.

.TP

Create or use an shared memory segment with numeric ID

.I id

.TP

Create or use an shared memory segment, with the ID generated

using

.I ftok(3)

from shmkeyfile

.TP

Set policy for a file in tmpfs or hugetlbfs

.TP

Touch pages to enforce policy early. Default is to not touch them, the policy

is applied when an applications maps and accesses a page.

.TP

Dump policy in the specified range.

.TP

.TS

tab(:);

l l.

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.

.TE

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 \-\-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 regiion specified by

/tmp/shmkey over all nodes.

numactl --offset=1G --length=1G --membind=1 --file /hugetlbfs/A --touch

Bind the second gigabyte in the hugetlbfs file /hugetlbfs/A to node 1.

numactl --localalloc /shmfs/file

Reset the policy for the shared memory file

.I file

to the default localalloc policy.

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.

.I /proc/cpuinfo

for the listing of active CPUs. See

.I proc(5)

for details.

.I /sys/devices/system/node/node*/numastat

for NUMA memory hit statistics.

.I set_mempolicy(2)

,

.I get_mempolicy(2)

,

.I mbind(2)

,

.I sched_setaffinity(2)

,

.I sched_getaffinity(2)

,

.I proc(5)

,

.I ftok(3)

,

.I shmat(2)