numastat(8) — Linux manual page


numastat(8)                  Administration                  numastat(8)

NAME         top

       numastat - Show per-NUMA-node memory statistics for processes and
       the operating system

SYNTAX         top


       numastat [-V]

       numastat [<PID>|<pattern>...]

       numastat [-c] [-m] [-n] [-p <PID>|<pattern>] [-s[<node>]] [-v]
       [-z] [<PID>|<pattern>...]

DESCRIPTION         top

       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 memory) in these

       numa_hit is memory successfully allocated on this node as

       numa_miss is memory allocated on this node despite the process
       preferring 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
       significantly 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 described below.

       Memory usage information reflects the resident pages on the

OPTIONS         top

       -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 information similar to that found in

       -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 assumed 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 remaining
              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

              Sort the table data in descending order before displaying
              it, so the biggest memory consumers are listed first.
              With no specified <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
              information for multiple processes will display detailed
              information for each process.  Normally when per-node
              information for multiple 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         top

       numastat attempts to fold each table display so it will be
       conveniently readable on the output terminal.  Normally a
       terminal width of 80 characters is assumed.  When the resize
       command is available, numastat attempts 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
       NUMASTAT_WIDTH environment variable.  For example,
       NUMASTAT_WIDTH=100  numastat.  On systems with many NUMA nodes,
       numastat -c -z .... can be very helpful to selectively reduce the
       amount of displayed information.



FILES         top


EXAMPLES         top

       numastat -c -z -m -n
       numastat -czs libvirt kvm qemu
       watch -n1 numastat
       watch -n1 --differences=cumulative numastat

AUTHORS         top

       The original numastat perl script was written circa 2003 by Andi
       Kleen <>.  The current numastat program was
       written in 2012 by Bill Gray <> to be compatible
       by default with the original, and to add options to display per-
       node system memory usage and per-node process memory allocation.

SEE ALSO         top

       numactl(8), set_mempolicy(2), numa(3)

COLOPHON         top

       This page is part of the numactl (NUMA commands) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report
       for this manual page, send it to
       This page was obtained from the project's upstream Git repository
       ⟨⟩ on 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2024-06-10.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

Bill Gray                         1.0.0                      numastat(8)

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