LSCPU

Section: User Commands (1)
Updated: January 2013
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NAME

lscpu - display information about the CPU architecture

SYNOPSIS

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

DESCRIPTION

lscpu gathers CPU architecture information from sysfs and /proc/cpuinfo. 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.

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.

COLUMNS

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

BOOK

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

NODE

The logical NUMA node number. A node may contain several books.

CACHE

Information about how caches are shared between CPUs.

ADDRESS

The physical address of a CPU.

ONLINE

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

CONFIGURED

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.

POLARIZATION

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 polarization.

MMHZ: Maximum megaherz 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.

OPTIONS

-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.

-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 inspected.

-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).

-V, --version

Display version information and exit.

BUGS

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.

AUTHOR

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

AVAILABILITY

The lscpu command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.

Index

NAME

SYNOPSIS

DESCRIPTION

COLUMNS