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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | BUGS | AUTHORS | SEE ALSO | AVAILABILITY | COLOPHON |
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LSCPU(1) User Commands LSCPU(1)
lscpu - display information about the CPU architecture
lscpu [options]
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.
COLUMNS
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
cores.
CLUSTER
The logical cluster number. A cluster can contain several
cores.
BOOK The logical book number. A book can contain several
sockets.
DRAWER The logical drawer number. A drawer can contain several
books.
NODE The logical NUMA node number. A node can contain several
drawers.
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.
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.
-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, 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'.
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.
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.
Cai Qian <qcai@redhat.com>
Karel Zak <kzak@redhat.com>
Heiko Carstens <heiko.carstens@de.ibm.com>
chcpu(8)
The lscpu command is part of the util-linux package and is
available from
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
2021-03-21. (At that time, the date of the most recent commit
that was found in the repository was 2021-03-19.) 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 March 2019 LSCPU(1)
Pages that refer to this page: sched_setaffinity(2), proc(5), sched(7), chcpu(8)
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