sys-utils/lscpu.1

   1 .TH LSCPU 1 "March 2019" "util-linux" "User Commands"
   2 .SH NAME
   3 lscpu \- display information about the CPU architecture
   4 .SH SYNOPSIS
   5 .B lscpu
   6 [options]
   7 .SH DESCRIPTION
   8 .B lscpu
   9 gathers CPU architecture information from sysfs, /proc/cpuinfo and any
  10 applicable architecture-specific libraries (e.g.\& librtas on Powerpc).  The
  11 command output can be optimized for parsing or for easy readability by humans.
  12 The information includes, for example, the number of CPUs, threads, cores,
  13 sockets, and Non-Uniform Memory Access (NUMA) nodes.  There is also information
  14 about the CPU caches and cache sharing, family, model, bogoMIPS, byte order,
  15 and stepping.
  16 .sp
  17 In virtualized environments, the CPU architecture information displayed
  18 reflects the configuration of the guest operating system which is
  19 typically different from the physical (host) system.  On architectures that
  20 support retrieving physical topology information,
  21 .B lscpu
  22 also displays the number of physical sockets, chips, cores in the host system.
  23 .sp
  24 Options that result in an output table have a \fIlist\fP argument.  Use this
  25 argument to customize the command output.  Specify a comma-separated list of
  26 column labels to limit the output table to only the specified columns, arranged
  27 in the specified order.  See \fBCOLUMNS\fP for a list of valid column labels.  The
  28 column labels are not case sensitive.
  29 .sp
  30 Not all columns are supported on all architectures.  If an unsupported column is
  31 specified, \fBlscpu\fP prints the column but does not provide any data for it.
  32 .sp
  33 The default output formatting on terminal maybe optimized for better
  34 readability.  The output for non-terminals (e.g., pipes) is never affected by
  35 this optimization and it is always in "Field: data\\n" format.
  36 .sp
  37 The cache sizes are reported as summary from all CPUs.  The versions before
  38 v2.34 reported per-core sizes, but this output was confusing due to complicated
  39 CPUs topology and the way how caches are shared between CPUs. For more details
  40 about caches see \fB\-\-cache\fP.
  41 .SS COLUMNS
  42 Note that topology elements (core, socket, etc.) use a sequential unique ID
  43 starting from zero, but CPU logical numbers follow the kernel where there is
  44 no guarantee of sequential numbering.
  45 .TP
  46 .B CPU
  47 The logical CPU number of a CPU as used by the Linux kernel.
  48 .TP
  49 .B CORE
  50 The logical core number.  A core can contain several CPUs.
  51 .TP
  52 .B SOCKET
  53 The logical socket number.  A socket can contain several cores.
  54 .TP
  55 .B BOOK
  56 The logical book number.  A book can contain several sockets.
  57 .TP
  58 .B DRAWER
  59 The logical drawer number.  A drawer can contain several books.
  60 .TP
  61 .B NODE
  62 The logical NUMA node number.  A node can contain several drawers.
  63 .TP
  64 .B CACHE
  65 Information about how caches are shared between CPUs.
  66 .TP
  67 .B ADDRESS
  68 The physical address of a CPU.
  69 .TP
  70 .B ONLINE
  71 Indicator that shows whether the Linux instance currently makes use of the CPU.
  72 .TP
  73 .B CONFIGURED
  74 Indicator that shows if the hypervisor has allocated the CPU to the virtual
  75 hardware on which the Linux instance runs.  CPUs that are configured can be set
  76 online by the Linux instance.
  77 This column contains data only if your hardware system and hypervisor support
  78 dynamic CPU resource allocation.
  79 .TP
  80 .B POLARIZATION
  81 This column contains data for Linux instances that run on virtual hardware with
  82 a hypervisor that can switch the CPU dispatching mode (polarization).  The
  83 polarization can be:
  84 .RS
  85 .TP 12
  86 .B horizontal\fP
  87 The workload is spread across all available CPUs.
  88 .TP 12
  89 .B vertical
  90 The workload is concentrated on few CPUs.
  91 .P
  92 For vertical polarization, the column also shows the degree of concentration,
  93 high, medium, or low.  This column contains data only if your hardware system
  94 and hypervisor support CPU polarization.
  95 .RE
  96 .TP
  97 .B MAXMHZ
  98 Maximum megahertz value for the CPU. Useful when \fBlscpu\fP is used as hardware
  99 inventory information gathering tool.  Notice that the megahertz value is
 100 dynamic, and driven by CPU governor depending on current resource need.
 101 .TP
 102 .B MINMHZ
 103 Minimum megahertz value for the CPU.
 104 .SH OPTIONS
 105 .TP
 106 .BR \-a , " \-\-all"
 107 Include lines for online and offline CPUs in the output (default for \fB\-e\fR).
 108 This option may only be specified together with option \fB\-e\fR or \fB\-p\fR.
 109 .TP
 110 .BR \-B , " \-\-bytes"
 111 Print the sizes in bytes rather than in a human-readable format.
 112 .TP
 113 .BR \-b , " \-\-online"
 114 Limit the output to online CPUs (default for \fB\-p\fR).
 115 This option may only be specified together with option \fB\-e\fR or \fB\-p\fR.
 116 .TP
 117 .BR \-C , " \-\-caches" [=\fIlist\fP]
 118 Display details about CPU caches.  For details about available information see \fB\-\-help\fR
 119 output.
 120
 121 If the \fIlist\fP argument is omitted, all columns for which data is available
 122 are included in the command output.
 123
 124 When specifying the \fIlist\fP argument, the string of option, equal sign (=), and
 125 \fIlist\fP must not contain any blanks or other whitespace.
 126 Examples: '\fB\-C=NAME,ONE-SIZE\fP' or '\fB\-\-caches=NAME,ONE-SIZE\fP'.
 127 .TP
 128 .BR \-c , " \-\-offline"
 129 Limit the output to offline CPUs.
 130 This option may only be specified together with option \fB\-e\fR or \fB\-p\fR.
 131 .TP
 132 .BR \-e , " \-\-extended" [=\fIlist\fP]
 133 Display the CPU information in human-readable format.
 134
 135 If the \fIlist\fP argument is omitted, all columns for which data is available
 136 are included in the command output.
 137
 138 When specifying the \fIlist\fP argument, the string of option, equal sign (=), and
 139 \fIlist\fP must not contain any blanks or other whitespace.
 140 Examples: '\fB\-e=cpu,node\fP' or '\fB\-\-extended=cpu,node\fP'.
 141 .TP
 142 .BR \-h , " \-\-help"
 143 Display help text and exit.
 144 .TP
 145 .BR \-J , " \-\-json"
 146 Use JSON output format for the default summary or extended output (see \fB\-\-extended\fP).
 147 .TP
 148 .BR \-p , " \-\-parse" [=\fIlist\fP]
 149 Optimize the command output for easy parsing.
 150
 151 If the \fIlist\fP argument is omitted, the command output is compatible with earlier
 152 versions of \fBlscpu\fP.  In this compatible format, two commas are used to separate
 153 CPU cache columns.  If no CPU caches are identified the cache column is omitted.
 154 .br
 155 If the \fIlist\fP argument is used, cache columns are separated with a colon (:).
 156
 157 When specifying the \fIlist\fP argument, the string of option, equal sign (=), and
 158 \fIlist\fP must not contain any blanks or other whitespace.
 159 Examples: '\fB\-p=cpu,node\fP' or '\fB\-\-parse=cpu,node\fP'.
 160 .TP
 161 .BR \-s , " \-\-sysroot " \fIdirectory\fP
 162 Gather CPU data for a Linux instance other than the instance from which the
 163 \fBlscpu\fP command is issued.  The specified \fIdirectory\fP is the system root
 164 of the Linux instance to be inspected.
 165 .TP
 166 .BR \-x , " \-\-hex"
 167 Use hexadecimal masks for CPU sets (for example "ff").  The default is to print
 168 the sets in list format (for example 0,1).  Note that before version 2.30 the mask
 169 has been printed with 0x prefix.
 170 .TP
 171 .BR \-y , " \-\-physical"
 172 Display physical IDs for all columns with topology elements (core, socket, etc.).
 173 Other than logical IDs, which are assigned by \fBlscpu\fP, physical IDs are
 174 platform-specific values that are provided by the kernel. Physical IDs are not
 175 necessarily unique and they might not be arranged sequentially.
 176 If the kernel could not retrieve a physical ID for an element \fBlscpu\fP prints
 177 the dash (-) character.
 178
 179 The CPU logical numbers are not affected by this option.
 180 .TP
 181 .BR \-V , " \-\-version"
 182 Display version information and exit.
 183 .TP
 184 .B \-\-output\-all
 185 Output all available columns.  This option must be combined with either
 186 .BR \-\-extended ", " \-\-parse " or " \-\-caches .
 187 .SH BUGS
 188 The basic overview of CPU family, model, etc. is always based on the first
 189 CPU only.
 190
 191 Sometimes in Xen Dom0 the kernel reports wrong data.
 192
 193 On virtual hardware the number of cores per socket, etc. can be wrong.
 194 .SH AUTHOR
 195 .nf
 196 Cai Qian <qcai@redhat.com>
 197 Karel Zak <kzak@redhat.com>
 198 Heiko Carstens <heiko.carstens@de.ibm.com>
 199 .fi
 200 .SH "SEE ALSO"
 201 .BR chcpu (8)
 202 .SH AVAILABILITY
 203 The lscpu command is part of the util-linux package and is available from
 204 https://www.kernel.org/pub/linux/utils/util-linux/.