LSCPU(1)                        User Commands                       LSCPU(1)

NAME         top

       lscpu - display information about the CPU architecture

SYNOPSIS         top

       lscpu [-a|-b|-c|-J] [-x] [-y] [-s directory] [-e[=list]|-p[=list]]
       lscpu -h|-V

DESCRIPTION         top

       lscpu gathers CPU architecture information from sysfs, /proc/cpuinfo
       and any applicable architecture-specific libraries (e.g. librtas on
       Powerpc).  The command output can be optimized for parsing or for
       easy readability by humans.  The information includes, for example,
       the number of CPUs, threads, cores, sockets, and Non-Uniform Memory
       Access (NUMA) nodes.  There is also information about the CPU caches
       and cache sharing, family, model, bogoMIPS, byte order, and stepping.

       In virtualized environments, the CPU architecture information
       displayed reflects the configuration of the guest operating system
       which is typically different from the physical (host) system.  On
       architectures that support retrieving physical topology information,
       lscpu also displays the number of physical sockets, chips, cores in
       the host system.

       Options that result in an output table have a list argument.  Use
       this argument to customize the command output.  Specify a comma-
       separated list of column labels to limit the output table to only the
       specified columns, arranged in the specified order.  See COLUMNS for
       a list of valid column labels.  The column labels are not case

       Not all columns are supported on all architectures.  If an
       unsupported column is specified, lscpu prints the column but does not
       provide any data for it.

       Note that topology elements (core, socket, etc.) use a sequential
       unique ID starting from zero, but CPU logical numbers follow the
       kernel where there is no guarantee of sequential numbering.

       CPU    The logical CPU number of a CPU as used by the Linux kernel.

       CORE   The logical core number.  A core can contain several CPUs.

       SOCKET The logical socket number.  A socket can contain several

       BOOK   The logical book number.  A book can contain several sockets.

       DRAWER The logical drawer number.  A drawer can contain several

       NODE   The logical NUMA node number.  A node can contain several

       CACHE  Information about how caches are shared between CPUs.

              The physical address of a CPU.

       ONLINE Indicator that shows whether the Linux instance currently
              makes use of the CPU.

              Indicator that shows if the hypervisor has allocated the CPU
              to the virtual hardware on which the Linux instance runs.
              CPUs that are configured can be set online by the Linux
              instance.  This column contains data only if your hardware
              system and hypervisor support dynamic CPU resource allocation.

              This column contains data for Linux instances that run on
              virtual hardware with a hypervisor that can switch the CPU
              dispatching mode (polarization).  The polarization can be:

              horizontal  The workload is spread across all available CPUs.

              vertical    The workload is concentrated on few CPUs.

              For vertical polarization, the column also shows the degree of
              concentration, high, medium, or low.  This column contains
              data only if your hardware system and hypervisor support CPU

       MAXMHZ Maximum megahertz value for the CPU. Useful when lscpu is used
              as hardware inventory information gathering tool.  Notice that
              the megahertz value is dynamic, and driven by CPU governor
              depending on current resource need.

       MINMHZ Minimum megahertz value for the CPU.

OPTIONS         top

       -a, --all
              Include lines for online and offline CPUs in the output
              (default for -e).  This option may only be specified together
              with option -e or -p.

       -b, --online
              Limit the output to online CPUs (default for -p).  This option
              may only be specified together with option -e or -p.

       -c, --offline
              Limit the output to offline CPUs.  This option may only be
              specified together with option -e or -p.

       -e, --extended[=list]
              Display the CPU information in human-readable format.

              If the list argument is omitted, all columns for which data is
              available are included in the command output.

              When specifying the list argument, the string of option, equal
              sign (=), and list must not contain any blanks or other
              whitespace.  Examples: '-e=cpu,node' or '--extended=cpu,node'.

       -h, --help
              Display help text and exit.

       -J, --json
              Use JSON output format for the default summary or extended
              output (see --extended).

       -p, --parse[=list]
              Optimize the command output for easy parsing.

              If the list argument is omitted, the command output is
              compatible with earlier versions of lscpu.  In this compatible
              format, two commas are used to separate CPU cache columns.  If
              no CPU caches are identified the cache column is omitted.
              If the list argument is used, cache columns are separated with
              a colon (:).

              When specifying the list argument, the string of option, equal
              sign (=), and list must not contain any blanks or other
              whitespace.  Examples: '-p=cpu,node' or '--parse=cpu,node'.

       -s, --sysroot directory
              Gather CPU data for a Linux instance other than the instance
              from which the lscpu command is issued.  The specified
              directory is the system root of the Linux instance to be

       -x, --hex
              Use hexadecimal masks for CPU sets (for example 0x3).  The
              default is to print the sets in list format (for example 0,1).

       -y, --physical
              Display physical IDs for all columns with topology elements
              (core, socket, etc.).  Other than logical IDs, which are
              assigned by lscpu, physical IDs are platform-specific values
              that are provided by the kernel. Physical IDs are not
              necessarily unique and they might not be arranged
              sequentially.  If the kernel could not retrieve a physical ID
              for an element lscpu prints the dash (-) character.

              The CPU logical numbers are not affected by this option.

       -V, --version
              Display version information and exit.

              Output all available columns.  This option must be combined
              with either --extended or --parse.

BUGS         top

       The basic overview of CPU family, model, etc. is always based on the
       first CPU only.

       Sometimes in Xen Dom0 the kernel reports wrong data.

       On virtual hardware the number of cores per socket, etc. can be

AUTHOR         top

       Cai Qian <>
       Karel Zak <>
       Heiko Carstens <>

SEE ALSO         top


AVAILABILITY         top

       The lscpu command is part of the util-linux package and is available

COLOPHON         top

       This page is part of the util-linux (a random collection of Linux
       utilities) 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
       ⟨git://⟩ on
       2018-10-29.  (At that time, the date of the most recent commit that
       was found in the repository was 2018-10-24.)  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

util-linux                      November 2015                       LSCPU(1)

Pages that refer to this page: sched_setaffinity(2)proc(5)chcpu(8)