numastat(8) Administration numastat(8)
NAME
numastat - Show per-NUMA-node memory statistics for processes and the
operating system
SYNTAX
numastat
numastat [-V]
numastat [<PID>|<pattern>...]
numastat [-c] [-m] [-n] [-p <PID>|<pattern>] [-s[<node>]] [-v] [-z]
[<PID>|<pattern>...]
DESCRIPTION
numastat with no command options or arguments at all, displays per-node
NUMA hit and miss system statistics from the kernel memory allocator.
This default numastat behavior is strictly compatible with the previous
long-standing numastat perl script, written by Andi Kleen. The default
numastat statistics shows per-node numbers (in units of pages of mem-
ory) in these categories:
numa_hit is memory successfully allocated on this node as intended.
numa_miss is memory allocated on this node despite the process prefer-
ring some different node. Each numa_miss has a numa_foreign on another
node.
numa_foreign is memory intended for this node, but actually allocated
on some different node. Each numa_foreign has a numa_miss on another
node.
interleave_hit is interleaved memory successfully allocated on this
node as intended.
local_node is memory allocated on this node while a process was running
on it.
other_node is memory allocated on this node while a process was running
on some other node.
Any supplied options or arguments with the numastat command will sig-
nificantly change both the content and the format of the display.
Specified options will cause display units to change to megabytes of
memory, and will change other specific behaviors of numastat as de-
scribed below.
Memory usage information reflects the resident pages on the system.
OPTIONS
-c Minimize table display width by dynamically shrinking column
widths based on data contents. With this option, amounts of
memory will be rounded to the nearest megabyte (rather than the
usual display with two decimal places). Column width and inter-
column spacing will be somewhat unpredictable with this option,
but the more dense display will be very useful on systems with
many NUMA nodes.
-m Show the meminfo-like system-wide memory usage information.
This option produces a per-node breakdown of memory usage infor-
mation similar to that found in /proc/meminfo.
-n Show the original numastat statistics info. This will show the
same information as the default numastat behavior but the units
will be megabytes of memory, and there will be other formatting
and layout changes versus the original numastat behavior.
-p <PID> or <pattern>
Show per-node memory allocation information for the specified
PID or pattern. If the -p argument is only digits, it is as-
sumed to be a numerical PID. If the argument characters are not
only digits, it is assumed to be a text fragment pattern to
search for in process command lines. For example, numastat -p
qemu will attempt to find and show information for processes
with "qemu" in the command line. Any command line arguments re-
maining after numastat option flag processing is completed, are
assumed to be additional <PID> or <pattern> process specifiers.
In this sense, the -p option flag is optional: numastat qemu is
equivalent to numastat -p qemu
-s[<node>]
Sort the table data in descending order before displaying it, so
the biggest memory consumers are listed first. With no speci-
fied <node>, the table will be sorted by the total column. If
the optional <node> argument is supplied, the data will be
sorted by the <node> column. Note that <node> must follow the
-s immediately with no intermediate white space (e.g., numastat
-s2). Because -s can allow an optional argument, it must always
be the last option character in a compound option character
string. For example, instead of numastat -msc (which probably
will not work as you expect), use numastat -mcs
-v Make some reports more verbose. In particular, process informa-
tion for multiple processes will display detailed information
for each process. Normally when per-node information for multi-
ple processes is displayed, only the total lines are shown.
-V Display numastat version information and exit.
-z Skip display of table rows and columns of only zero valuess.
This can be used to greatly reduce the amount of uninteresting
zero data on systems with many NUMA nodes. Note that when rows
or columns of zeros are still displayed with this option, that
probably means there is at least one value in the row or column
that is actually non-zero, but rounded to zero for display.
NOTES
numastat attempts to fold each table display so it will be conveniently
readable on the output terminal. Normally a terminal width of 80 char-
acters is assumed. When the resize command is available, numastat at-
tempts to dynamically determine and fine tune the output tty width from
resize output. If numastat output is not to a tty, very long output
lines can be produced, depending on how many NUMA nodes are present.
In all cases, output width can be explicitly specified via the NUMAS-
TAT_WIDTH environment variable. For example, NUMASTAT_WIDTH=100 numa-
stat. On systems with many NUMA nodes, numastat -c -z .... can be very
helpful to selectively reduce the amount of displayed information.
ENVIRONMENT VARIABLES
NUMASTAT_WIDTH
FILES
/proc/*/numa_maps
/sys/devices/system/node/node*/meminfo
/sys/devices/system/node/node*/numastat
EXAMPLES
numastat -c -z -m -n
numastat -czs libvirt kvm qemu
watch -n1 numastat
watch -n1 --differences=cumulative numastat
AUTHORS
The original numastat perl script was written circa 2003 by Andi Kleen
<andi.kleen@intel.com>. The current numastat program was written in
2012 by Bill Gray <bgray@redhat.com> to be compatible by default with
the original, and to add options to display per-node system memory us-
age and per-node process memory allocation.
SEE ALSO
numactl(8), set_mempolicy(2), numa(3)
Bill Gray 1.0.0 numastat(8)
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