LSCPU(1) - phpMan

LSCPU(1) User Commands LSCPU(1)

NAME
lscpu - display information about the CPU architecture

SYNOPSIS
lscpu [options]

DESCRIPTION
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
-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
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
Cai Qian <qcai AT redhat.com>, Karel Zak <kzak AT redhat.com>, Heiko Carstens
<heiko.carstens AT de.com>