Eric pointed to me that cpu_info kstats now contain both the current CPU
frequency and the frequency range for each CPU. I hacked /usr/sbin/psrinfo a
bit to show this information when running psrinfo -v. It shows output like
this:
$ psrinfo -v
Status of virtual processor 0 as of: 12/04/2007 17:55:03
on-line since 11/26/2007 15:06:47.
The i386 processor operates at [1596 MHz - 2660 MHz] 2660 MHz,
and has an i387 compatible floating point processor.
...
The hacked psrinfo is attached.
- akolb
-------------- next part --------------
#!/usr/perl5/bin/perl
#
# CDDL HEADER START
#
# The contents of this file are subject to the terms of the
# Common Development and Distribution License (the "License").
# You may not use this file except in compliance with the License.
#
# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
# or http://www.opensolaris.org/os/licensing.
# See the License for the specific language governing permissions
# and limitations under the License.
#
# When distributing Covered Code, include this CDDL HEADER in each
# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
# If applicable, add the following below this CDDL HEADER, with the
# fields enclosed by brackets "[]" replaced with your own identifying
# information: Portions Copyright [yyyy] [name of copyright owner]
#
# CDDL HEADER END
#
# Copyright 2007 Sun Microsystems, Inc. All rights reserved.
# Use is subject to license terms.
#
#ident "@(#)psrinfo.pl 1.22 07/07/18 SMI"
#
# psrinfo: displays information about processors
#
# See detailed comment in the end of this file.
#
use strict;
use warnings;
use locale;
use POSIX qw(locale_h strftime);
use File::Basename;
use Getopt::Long qw(:config no_ignore_case bundling auto_version);
use Sun::Solaris::Utils qw(textdomain gettext);
use Sun::Solaris::Kstat;
# Set message locale
setlocale(LC_ALL, "");
textdomain("SUNW_OST_OSCMD");
######################################################################
# Configuration variables
######################################################################
# Regexp describing cpu_info kstat fields describing CPU hierarchy.
my $valid_id_exp = qr{^(?:chip|core)_id$};
# Translation of kstat name to human-readable form
my %translations = ('chip_id' => gettext("The physical processor"),
'core_id' => gettext("The core"));
# Localized version of plural forms
my %pluralized_names = ('processor' => gettext("processor"),
'processors' => gettext("processors"),
'chip' => gettext("chip"),
'chips' => gettext("chips"),
'core' => gettext("core"),
'cores' => gettext("cores"));
# Localized CPU states
my %cpu_states = ('on-line' => gettext("on-line"),
'off-line' => gettext("off-line"),
'faulted' => gettext("faulted"),
'powered-off' => gettext("powered-off"),
'no-intr' => gettext("no-intr"),
'spare' => gettext("spare"),
'unknown' => gettext("unknown"));
######################################################################
# Global variables
######################################################################
# Hash with CPU ID as a key and specific per-cpu kstat hash as a value
our %cpu_list;
# Command name without path and trailing .pl - used for error messages.
our $cmdname = basename($0, ".pl");
# Return value
our $errors = 0;
######################################################################
# Helper subroutines
######################################################################
#
# Print help string if specified or the standard help message and exit setting
# errno.
#
sub usage
{
my (@msg) = @_;
print STDERR $cmdname, ": @msg\n" if (@msg);
print STDERR gettext("usage: \n" .
"\tpsrinfo [-v] [-p] [processor_id ...]\n" .
"\tpsrinfo -s [-p] processor_id\n");
exit(2);
}
#
# Return the input list with duplicates removed.
# Count how many times we've seen each element and remove elements seen more
# than once.
#
sub uniq
{
my %seen; # Have we seen this element already?
return (grep { ++$seen{$_} == 1 } @_);
}
#
# Return the intersection of two lists passed by reference
# Convert the first list to a hash with seen entries marked as 1-values
# Then grep only elements present in the first list from the second list.
# As a little optimization, use the shorter list to build a hash.
#
sub intersect
{
my ($left, $right) = @_;
my %seen; # Set to 1 for everything in the first list
# Put the shortest list in $left
scalar @$left <= scalar @$right or ($right, $left) = ($left, $right);
# Create a hash indexed by elements in @left with ones as a value.
map { $seen{$_} = 1 } @$left;
# Find members of @right present in @left
return (grep { $seen{$_} } @$right);
}
#
# Return elements of the second list not present in the first list. Both lists
# are passed by reference.
#
sub set_subtract
{
my ($left, $right) = @_;
my %seen; # Set to 1 for everything in the first list
# Create a hash indexed by elements in @left with ones as a value.
map { $seen{$_} = 1 } @$left;
# Find members of @right present in @left
return (grep { ! $seen{$_} } @$right);
}
#
# Sort the list numerically
# Should be called in list context
#
sub nsort
{
return (sort { $a <=> $b } @_);
}
#
# Sort list numerically and remove duplicates
# Should be called in list context
#
sub uniqsort
{
return (sort { $a <=> $b } uniq(@_));
}
#
# Return the maximum value of its arguments
#
sub max
{
my $m = shift;
foreach my $el (@_) {
$m = $el if $m < $el;
}
return ($m);
}
#
# Pluralize name if there is more than one instance
# Arguments: name, ninstances
#
sub pluralize
{
my ($name, $count) = @_;
# Remove trailing '_id' from the name.
$name =~ s/_id$//;
my $plural_name = $count > 1 ? "${name}s" : $name;
return ($pluralized_names{$plural_name} || $plural_name)
}
#
# Translate id name into printable form
# Look at the %translations table and replace everything found there
# Remove trailing _id from the name if there is no translation
#
sub id_translate
{
my $name = shift or return;
my $translated_name = $translations{$name};
$name =~ s/_id$// unless $translated_name;
return ($translated_name || $name);
}
#
# Consolidate consequtive CPU ids as start-end
# Input: list of CPUs
# Output: string with space-sepated cpu values with CPU ranges
# collapsed as x-y
#
sub collapse
{
return ('') unless @_;
my @args = uniqsort(@_);
my $start = shift(@args);
my $result = '';
my $end = $start; # Initial range consists of the first element
foreach my $el (@args) {
if ($el == ($end + 1)) {
#
# Got consecutive ID, so extend end of range without
# printing anything since the range may extend further
#
$end = $el;
} else {
#
# Next ID is not consecutive, so print IDs gotten so
# far.
#
if ($end > $start + 1) { # range
$result = "$result $start-$end";
} elsif ($end > $start) { # different values
$result = "$result $start $end";
} else { # same value
$result = "$result $start";
}
# Try finding consecutive range starting from this ID
$start = $end = $el;
}
}
# Print last ID(s)
if ($end > $start + 1) {
$result = "$result $start-$end";
} elsif ($end > $start) {
$result = "$result $start $end";
} else {
$result = "$result $start";
}
# Remove any spaces in the beginning
$result =~ s/^\s+//;
return ($result);
}
#
# Expand start-end into the list of values
# Input: string containing a single numeric ID or x-y range
# Output: single value or a list of values
# Ranges with start being more than end are inverted
#
sub expand
{
my $arg = shift;
if ($arg =~ m/^\d+$/) {
# single number
return ($_);
} elsif ($arg =~ m/^(\d+)\-(\d+)$/) {
my ($start, $end) = ($1, $2); # $start-$end
# Reverse the interval if start > end
($start, $end) = ($end, $start) if $start > $end;
return ($start .. $end);
} elsif ($arg =~ m/-/) {
printf STDERR
gettext("%s: invalid processor range %s\n"),
$cmdname, $_;
} else {
printf STDERR
gettext("%s: processor %s: Invalid argument\n"),
$cmdname, $_;
}
$errors = 2;
return ();
}
#
# Functions for constructing CPU hierarchy. Only used with -vp option.
#
#
# Return numerically sorted list of distinct values of a given cpu_info kstat
# field, spanning given CPU set.
#
# Arguments:
# Property name
# list of CPUs
#
# Treat undefined values as zeroes.
sub property_list
{
my $prop_name = shift;
return (grep {$_ >= 0} uniqsort(map { $cpu_list{$_}->{$prop_name} || 0
} @_));
}
#
# Return subset of CPUs sharing specified value of a given cpu_info kstat field.
# Arguments:
# Property name
# Property value
# List of CPUs to select from
#
# Treat undefined values as zeroes.
sub cpus_by_prop
{
my $prop_name = shift;
my $prop_val = shift;
return (grep { ($cpu_list{$_}->{$prop_name} || 0) == $prop_val } @_);
}
#
# Build component tree
#
# Arguments:
# Reference to the list of CPUs sharing the component
# Reference to the list of sub-components
#
sub build_component_tree
{
my ($cpus, $comp_list) = @_;
# Get the first component and the rest
my ($comp_name, @comps) = @$comp_list;
my $tree = {};
if (!$comp_name) {
$tree->{cpus} = $cpus;
return ($tree);
}
# Get all possible component values
foreach my $v (property_list($comp_name, @$cpus)) {
my @comp_cpus = cpus_by_prop ($comp_name, $v, @$cpus);
$tree->{name} = $comp_name;
$tree->{cpus} = $cpus;
$tree->{values}->{$v} = build_component_tree(\...@comp_cpus,
\...@comps);
}
return ($tree);
}
#
# Print the component tree
# Arguments:
# Reference to a tree
# indentation
# Output: maximum indentation
#
sub print_component_tree
{
my ($tree, $ind) = @_;
my $spaces = ' ' x $ind; # indentation string
my $vals = $tree->{values};
my $retval = $ind;
if ($vals) {
# This is not a leaf node
# Get node name and translate it to printable format
my $id_name = id_translate($tree->{name});
# Examine each sub-node
foreach my $comp_val (nsort(keys %$vals)) {
my $child_tree = $vals->{$comp_val}; # Sub-tree
my $child_id = $child_tree->{name}; # Name of child node
my @cpus = @{$child_tree->{cpus}}; # CPUs for the child
my $ncpus = scalar @cpus; # Number of CPUs
my $cpuname = pluralize('processor', $ncpus);
my $cl = collapse(@cpus); # Printable CPU list
if (!$child_id) {
# Child is a leaf node
print $spaces;
printf gettext("%s has %d virtual %s"),
$id_name, $ncpus, $cpuname;
print " ($cl)\n";
$retval = max($retval, $ind + 2);
} else {
# Child has several values. Let's see how many
my $grandchild_tree = $child_tree->{values};
my $nvals = scalar(keys %$grandchild_tree);
my $child_id_name = pluralize($child_id,
$nvals);
print $spaces;
printf
gettext("%s has %d %s and %d virtual %s"),
$id_name, $nvals, $child_id_name, $ncpus,
$cpuname;
print " ($cl)\n";
# Print the tree for the child
$retval = max($retval,
print_component_tree($child_tree,
$ind + 2));
}
}
}
return ($retval);
}
#
# Get CPU frequency from cpu_info kstat for a given CPU. The frequency is
# obtained from current_clock_Hz field if it is present and from clock_MHz if
# current_clock_Hz is not present.
#
# In case multiple CPU frequencies are reported in supported_frequencies_Hz
# field , the range is also displayed.
#
sub get_frequency
{
my $cpu = shift;
my $clock_MHz = $cpu->{'clock_MHz'};
my $current_clock = $cpu->{'current_clock_Hz'};
my $supported_frequencies = $cpu->{'supported_frequencies_Hz'};
my @frequencies = split(/:/, $supported_frequencies);
return $clock_MHz unless $current_clock;
# Convert frequency to MHz
$current_clock = int(($current_clock + 500000)/ 1000000);
return $current_clock if scalar @frequencies <= 1;
my $min_freq = shift @frequencies;
my $max_freq = $min_freq;
foreach my $f (@frequencies) {
$min_freq = $f if $f < $min_freq;
$max_freq = $f if $f >max $min_freq;
}
return $current_clock if scalar $min_freq == $max_freq;
$min_freq = int(($min_freq + 500000)/ 1000000);
$max_freq = int(($max_freq + 500000)/ 1000000);
return "[$min_freq MHz - $max_freq MHz] $current_clock"
}
############################
# Main part of the program
############################
#
# Option processing
#
my ($opt_v, $opt_p, $opt_silent);
GetOptions("p" => \$opt_p,
"v" => \$opt_v,
"s" => \$opt_silent) || usage();
my $verbosity = 1;
my $phys_view;
$verbosity |= 2 if $opt_v;
$verbosity &= ~1 if $opt_silent;
$phys_view = 1 if $opt_p;
# Set $phys_verbose if -vp is specified
my $phys_verbose = $phys_view && ($verbosity > 1);
# Verify options
usage(gettext("options -s and -v are mutually exclusive")) if $verbosity == 2;
usage(gettext("must specify exactly one processor if -s used")) if
(($verbosity == 0) && scalar @ARGV != 1);
#
# Read cpu_info kstats
#
my $ks = Sun::Solaris::Kstat->new(strip_strings => 1) or
(printf STDERR gettext("%s: kstat_open() failed: %s\n"),
$cmdname, $!),
exit(2);
my $cpu_info = $ks->{cpu_info} or
(printf STDERR gettext("%s: can not read cpu_info kstats\n"),
$cmdname),
exit(2);
my (
@all_cpus, # List of all CPUs in the system
@cpu_args, # CPUs to look at
@cpus, # List of CPUs to process
@id_list, # list of various xxx_id kstats representing CPU topology
%chips, # Hash with chip ID as a key and reference to the list of
# virtual CPU IDs, belonging to the chip as a value
@chip_list, # List of all chip_id values
$ctree, # The component tree
);
#
# Get information about each CPU.
#
# Collect list of all CPUs in @cpu_list array
#
# Construct %cpu_list hash keyed by CPU ID with cpu_info kstat hash as its
# value.
#
# Construct %chips hash keyed by chip ID. It has a 'cpus' entry, which is
# a reference to a list of CPU IDs within a chip.
#
foreach my $id (nsort(keys %$cpu_info)) {
# $id is CPU id
my $info = $cpu_info->{$id};
#
# The name part of the cpu_info kstat should always be a string
# cpu_info$id.
#
# The $ci hash reference holds all data for a specific CPU id.
#
my $ci = $info->{"cpu_info$id"} or next;
# Save CPU-specific information in cpu_list hash, indexed by CPU ID.
$cpu_list{$id} = $ci;
my $chip_id = $ci->{'chip_id'};
# Collect CPUs within the chip.
# $chips{$chip_id} is a reference to a list of CPU IDs belonging to thie
# chip. It is automatically created when first referenced.
push (@{$chips{$chip_id}}, $id) if (defined($chip_id));
# Collect list of CPU IDs in @cpus
push (@all_cpus, $id);
}
#
# Figure out what CPUs to examine.
# Look at specific CPUs if any are specified on the command line or at all CPUs
# CPU ranges specified in the command line are expanded into lists of CPUs
#
if (scalar(@ARGV) == 0) {
@cpu_args = @all_cpus;
} else {
# Expand all x-y intervals in the argument list
@cpu_args = map { expand($_) } @ARGV;
usage(gettext("must specify exactly one processor if -s used")) if
(($verbosity == 0) && scalar @cpu_args != 1);
# Detect invalid CPUs in the arguments
my @bad_args = set_subtract(\...@all_cpus, \...@cpu_args);
my $nbadargs = scalar @bad_args;
if ($nbadargs != 0) {
# Warn user about bad CPUs in the command line
my $argstr = collapse(@bad_args);
if ($nbadargs > 1) {
printf STDERR gettext("%s: Invalid processors %s\n"),
$cmdname, $argstr;
} else {
printf STDERR
gettext("%s: processor %s: Invalid argument\n"),
$cmdname, $argstr;
}
$errors = 2;
}
@cpu_args = uniqsort(intersect(\...@all_cpus, \...@cpu_args));
}
#
# In physical view, CPUs specified in the command line are only used to identify
# chips. The actual CPUs are all CPUs belonging to these chips.
#
if (! $phys_view) {
@cpus = @cpu_args;
} else {
# Get list of chips spanning all CPUs specified
@chip_list = property_list('chip_id', @cpu_args);
if (!scalar @chip_list && $errors == 0) {
printf STDERR
gettext("%s: Physical processor view not supported\n"),
$cmdname;
exit(1);
}
# Get list of all CPUs within these chips
@cpus = uniqsort(map { @{$chips{$_}} } @chip_list);
}
if ($phys_verbose) {
#
# 1) Look at all possible xxx_id properties and remove those that have
# NCPU values or one value. Sort the rest.
#
# 2) Drop ids which have the same number of entries as number of CPUs or
# number of chips.
#
# 3) Build the component tree for the system
#
foreach my $id (keys %$cpu_info) {
my $info = $cpu_info->{$id};
my $name = "cpu_info$id";
my $ci = $info->{$name}; # cpu_info kstat for this CPU
# Collect all statistic names matching $valid_id_exp
push @id_list, grep(/$valid_id_exp/, keys(%$ci));
}
# Remove duplicates
@id_list = uniq(@id_list);
my $ncpus = scalar @cpus;
my %prop_nvals; # Number of instances of each property
my $nchips = scalar @chip_list;
#
# Get list of properties which have more than ncpus and less than nchips
# instances.
# Also collect number of instances for each property.
#
@id_list = grep {
my @ids = property_list($_, @cpus);
my $nids = scalar @ids;
$prop_nvals{$_} = $nids;
($_ eq "chip_id") ||
(($nids > $nchips) && ($nids > 1) && ($nids < $ncpus));
} @id_list;
# Sort @id_list by number of instances for each property
@id_list = sort { $prop_nvals{$a} <=> $prop_nvals{$b} } @id_list;
$ctree = build_component_tree(\...@cpus, \...@id_list);
}
#
# Walk all CPUs specified and print information about them.
# Do nothing for physical view - will do everything later.
#
foreach my $id (@cpus) {
last if $phys_view; # physical view is handled later
my $cpu = $cpu_list{$id} or next;
# Get CPU state and its modification time
my $mtime = $cpu->{'state_begin'};
my $mstring = strftime(gettext("%m/%d/%Y %T"), localtime($mtime));
my $status = $cpu->{'state'} || gettext("unknown");
# Get localized version of CPU status
$status = $cpu_states{$status} || $status;
if ($verbosity == 0) {
# Print 1 if CPU is online, 0 if offline.
printf "%d\n", $status eq 'on-line';
} elsif (! ($verbosity & 2)) {
printf gettext("%d\t%-8s since %s\n"),
$id, $status, $mstring;
} else {
printf gettext("Status of virtual processor %d as of: "), $id;
print strftime(gettext("%m/%d/%Y %T"), localtime());
print "\n";
printf gettext(" %s since %s.\n"), $status, $mstring;
my $clock_speed = get_frequency($cpu);
my $cpu_type = $cpu->{'cpu_type'};
# Display clock speed
if ($clock_speed ) {
printf
gettext(" The %s processor operates at %s MHz,\n"),
$cpu_type, $clock_speed;
} else {
printf
gettext(" the %s processor operates at an unknown frequency,\n"),
$cpu_type;
}
# Display FPU type
my $fpu = $cpu->{'fpu_type'};
if (! $fpu) {
print
gettext("\tand has no floating point processor.\n");
} elsif ($fpu =~ m/^[aeiouy]/) {
printf
gettext("\tand has an %s floating point processor.\n"),
$fpu;
} else {
printf
gettext("\tand has a %s floating point processor.\n"),
$fpu;
}
}
}
#
# Physical view print
#
if ($phys_view) {
if ($verbosity == 1) {
print scalar @chip_list, "\n";
} elsif ($verbosity == 0) {
# Print 1 if all CPUs are online, 0 otherwise.
foreach my $chip_id (@chip_list) {
# Get CPUs on a chip
my @chip_cpus = uniqsort(@{$chips{$chip_id}});
# List of all on-line CPUs on a chip
my @online_cpus = grep {
($cpu_list{$_}->{state}) eq 'on-line'
} @chip_cpus;
#
# Print 1 if number of online CPUs equals number of all
# CPUs
#
printf
"%d\n", scalar @online_cpus == scalar @chip_cpus;
}
} else {
# Walk the property tree and print everything in it.
my $tcores = $ctree->{values};
my $cname = id_translate($ctree->{name});
foreach my $chip (nsort(keys %$tcores)) {
my $chipref = $tcores->{$chip};
my @chip_cpus = @{$chipref->{cpus}};
my $ncpus = scalar @chip_cpus;
my $cpu_id = $chip_cpus[0];
my $cpu = $cpu_list{$cpu_id};
my $brand = $cpu->{brand} || gettext("(unknown)");
my $impl = $cpu->{implementation} ||
gettext("(unknown)");
#
# Remove cpuid and chipid information from
# implementation string and print it.
#
$impl =~ s/(cpuid|chipid)\s*\w+\s+//;
$brand = '' if $impl && $impl =~ /^$brand/;
# List of CPUs on a chip
my $cpu_name = pluralize('processor', $ncpus);
# Collapse range of CPUs into a-b string
my $cl = collapse(@chip_cpus);
my $childname = $chipref->{name};
if (! $childname) {
printf gettext("%s has %d virtual %s "),
$cname, $ncpus, $cpu_name;
print "($cl)\n";
print " $impl\n" if $impl;
print "\t$brand\n" if $brand;
} else {
# Get child count
my $nchildren =
scalar(keys(%{$chipref->{values}}));
$childname = pluralize($childname, $nchildren);
printf
gettext("%s has %d %s and %d virtual %s "),
$cname, $nchildren, $childname, $ncpus,
$cpu_name;
print "($cl)\n";
my $ident = print_component_tree ($chipref, 2);
my $spaces = ' ' x $ident;
print "$spaces$impl\n" if $impl;
print "$spaces $brand\n" if $brand;
}
}
}
}
exit($errors);
__END__
# The psrinfo command displays information about virtual and physical processors
# in a system. It gets all the information from the 'cpu_info' kstat.
#
# See detailed comment in the end of this file.
#
#
#
# This kstat
# has the following components:
#
# module: cpu_info
# instance: CPU ID
# name: cpu_infoID where ID is CPU ID
# class: misc
#
# The psrinfo command translates this information from kstat-specific
# representation to user-friendly format.
#
# The psrinfo command has several basic modes of operations:
#
# 1) Without options, it displays a line per CPU with CPU ID and its status and
# the time the status was last set in the following format:
#
# 0 on-line since MM/DD/YYYY HH:MM:SS
# 1 on-line since MM/DD/YYYY HH:MM:SS
# ...
#
# In this mode, the psrinfo command walks the list of CPUs (either from a
# command line or all CPUs) and prints the 'state' and 'state_begin' fields
# of cpu_info kstat structure for each CPU. The 'state_begin' is converted to
# local time.
#
# 2) With -s option and a single CPU ID as an argument, it displays 1 if the CPU
# is online and 0 otherwise.
#
# 3) With -p option, it displays the number of physical processors in a system.
# If any CPUs are specified in the command line, it displays the number of
# physical processors containing all virtual CPUs specified. The physical
# processor is identified by the 'chip_id' field of the cpu_info kstat.
#
# The code just walks over all CPUs specified and checks how many different
# core_id values they span.
#
# 4) With -v option, it displays several lines of information per virtual CPU,
# including its status, type, operating speed and FPU type. For example:
#
# Status of virtual processor 0 as of: MM/DD/YYYY HH:MM:SS
# on-line since MM/DD/YYYY HH:MM:SS.
# The i386 processor operates at XXXX MHz,
# and has an i387 compatible floating point processor.
# Status of virtual processor 1 as of: MM/DD/YYYY HH:MM:SS
# on-line since MM/DD/YYYY HH:MM:SS.
# The i386 processor operates at XXXX MHz,
# and has an i387 compatible floating point processor.
#
# This works in the same way as 1), just more kstat fields are massaged in the
# output.
#
# 5) With -vp option, it reports additional information about each physical
# processor. This information includes information about sub-components of
# each physical processor and virtual CPUs in each sub-component. For
# example:
#
# The physical processor has 2 cores and 4 virtual processors (0-3)
# The core has 2 virtual processors (0 1)
# The core has 2 virtual processors (2 3)
# x86 (GenuineIntel family 15 model 4 step 4 clock 3211 MHz)
# Intel(r) Pentium(r) D CPU 3.20GHz
#
# The implementation does not know anything about physical CPU components
# such as cores. Instead it looks at various cpu_info kstat statistics that
# look like xxx_id and tries to reconstruct the CPU hierarchy based on these
# fields. This works as follows:
#
# a) All kstats statistic names matching the $valid_id_exp regular expression
# are examined and each kstat statistic name is associated with the number
# of distinct entries in it.
#
# b) The resulting list of kstat statistic names is sorted according to the
# number of distinct entries, matching each name. For example, there are
# fewer chip_id values than core_id values. This implies that the core is
# a sub-component of a chip.
#
# c) All kstat names that have the same number of values as the number of
# physical processors ('chip_id' values) or the number of virtual
# processors are removed from the list.
#
# d) The resulting list represents the CPU hierarchy of the machine. It is
# translated into a tree showing the hardware hierarchy. Each level of the
# hierarchy contains the name, reference to a list of CPUs at this level
# and subcomponents, indexed by the value of each component.
# The example system above is represented by the following tree:
#
# $tree =
# {
# 'name' => 'chip_id',
# 'cpus' => [ '0', '1', '2', '3' ]
# 'values' =>
# {
# '0' =>
# {
# 'name' => 'core_id',
# 'cpus' => [ '0', '1', '2', '3' ]
# 'values' =>
# {
# '0' => { 'cpus' => [ '0', '1' ] }
# '1' => { 'cpus' => [ '2', '3' ] },
# },
# }
# },
# };
#
# Each node contains reference to a list of virtual CPUs at this level of
# hierarchy - one list for a system as a whole, one for chip 0 and one two
# for each cores. node. Non-leaf nodes also contain the symbolic name of
# the component as represented in the cpu_info kstat and a hash of
# subnodes, indexed by the value of the component. The tree is built by
# the build_component_tree() function.
#
# e) The resulting tree is pretty-printed showing the number of
# sub-components and virtual CPUs in each sub-component. The tree is
# printed by the print_component_tree() function.
#
