lscpu(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | BUGS | AUTHORS | SEE ALSO | REPORTING BUGS | AVAILABILITY

LSCPU(1)                      User Commands                     LSCPU(1)

NAME         top

       lscpu - display information about the CPU architecture

SYNOPSIS         top

       lscpu [options]

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.

       The default output formatting on terminal is subject to change
       and maybe optimized for better readability. The output for
       non-terminals (e.g., pipes) is never affected by this
       optimization and it is always in "Field: data\n" format. Use for
       example "lscpu | less" to see the default output without
       optimizations.

       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 sensitive.

       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.

       The cache sizes are reported as summary from all CPUs. The
       versions before v2.34 reported per-core sizes, but this output
       was confusing due to complicated CPUs topology and the way how
       caches are shared between CPUs. For more details about caches see
       --cache. Since version v2.37 lscpu follows cache IDs as provided
       by Linux kernel and it does not always start from zero.

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, --bytes
           Print the sizes in bytes rather than in a human-readable
           format.

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

       -C, --caches[=list]
           Display details about CPU caches. For details about available
           information see --help output.

           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: '-C=NAME,ONE-SIZE' or
           '--caches=NAME,ONE-SIZE'.

           The default list of columns may be extended if list is
           specified in the format +list (e.g., lscpu -C=+ALLOC-POLICY).

       -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, the default columns are
           included in the command output. The default output is subject
           to change.

           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'.

           The default list of columns may be extended if list is
           specified in the format +list (e.g., lscpu -e=+MHZ).

       -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'.

           The default list of columns may be extended if list is
           specified in the format +list (e.g., lscpu -p=+MHZ).

       -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
           inspected.

       -x, --hex
           Use hexadecimal masks for CPU sets (for example "ff"). The
           default is to print the sets in list format (for example
           0,1). Note that before version 2.30 the mask has been printed
           with 0x prefix.

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

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
       wrong.

AUTHORS         top

       Cai Qian <qcai@redhat.com>, Karel Zak <kzak@redhat.com>, Heiko
       Carstens <heiko.carstens@de.ibm.com>

SEE ALSO         top

       chcpu(8)

REPORTING BUGS         top

       For bug reports, use the issue tracker at
       https://github.com/karelzak/util-linux/issues.

AVAILABILITY         top

       The lscpu command is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>. This page
       is part of the util-linux (a random collection of Linux
       utilities) project. Information about the project can be found at
       ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
       a bug report for this manual page, send it to
       util-linux@vger.kernel.org. This page was obtained from the
       project's upstream Git repository
       ⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
       2021-08-27. (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-24.) 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 man-pages@man7.org

util-linux 2.37.85-637cc       2021-06-17                       LSCPU(1)

Pages that refer to this page: sched_setaffinity(2)proc(5)sched(7)chcpu(8)