Best Practices When Deploying Linux on the HP ProLiant DL980 (updated December 2012)

9
The following illustrates the relative distances between the nodes shown in Figure 4:
Shortest
distance

Intra
nodes

Nodes
sharing the
same
QPI island

Nodes on the
same side
of a node controller
(XNC)

All other nodes
on the other side
of the XNC

Longest
distance
(such as
node 0 to
node 0)
(such as
nodes 0
and 1)
(such as between
nodes 0–1
and 2–3)
(such as between
nodes 0–1
and 4–7)
Displaying task information
You can also use numactl command to display the memory allocation policy and processor affinity for the current
shell. The following example shows the default NUMA task policy and CPU bindings:
[root@tux ~]# numactl --show
policy: default
preferred node: current
physcpubind: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67
68 69 70 71 72 73 74 75 76 77 78 79
cpubind: 0 1 2 3 4 5 6 7
nodebind: 0 1 2 3 4 5 6 7
membind: 0 1 2 3 4 5 6 7
In this example, there is no specific binding because the current shell can be placed anywhere in the system and use any
memory location. For an example showing the use of the numactl command for performing an explicit binding, see
the “Controlling tasks and memory object placement” section. For more examples, see the numactl(8) manpage.
In addition to displaying CPU and memory bindings, the numactl command can control NUMA policies for shared
memory. For more information, see the numactl(8)manpage.
Note
The --show option does not allow specification of a particular process for
viewing.
Displaying memory allocation statistics
To display memory allocation statistics per NUMA node, use the numastat command. For example:
[root@tux ~]# numastat
node0 node1 node2 node3
numa_hit 72906006 61424717 60127482 43804361
numa_miss 0 0 0 0
numa_foreign 0 0 0 0
interleave_hit 3962072 3960669 3962517 3960688
local_node 69431708 57426131 56144944 39824458
other_node 3474298 3998586 3982538 3979903
node4 node5 node6 node7
numa_hit 39135067 30389110 16815956 9464732
numa_miss 0 0 0 0
numa_foreign 0 0 0 0
interleave_hit 3962009 3960766 3961914 3960446
local_node 35667858 26395324 14450038 6775752
other_node 3467209 3993786 2365918 2688980