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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.
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 default output formatting on terminal 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.
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.
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.
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'.
-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
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
2020-06-09. (At that time, the date of the most recent commit that
was found in the repository was 2020-06-08.) 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_getaffinity(2), sched_setaffinity(2), proc(5), procfs(5), sched(7), chcpu(8)
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