/usr/share/munin/plugins/buddyinfo is in munin-node 1.4.6-3ubuntu3.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 | #!/usr/bin/perl -w
=pod
=encoding UTF-8
=head1 NAME
buddyinfo - Plugin to monitor memory fragmentation on Linux systems.
=head1 APPLICABLE SYSTEMS
Linux 2.5.40+, 2.6.x
=head1 CONFIGURATION
None needed.
=head1 INTERPRETATION
Linux manages virtual memory on a page granularity. There are some operations
however that require physically contiguous pages to be allocated by the kernel.
Such allocations may fail if the memory gets fragmented and even though there
are enough pages free, but they are not contiguous.
This plugin monitors the amount of contiguous areas, called higher order pages.
The order means the exponent of two of the size of the area, so order 2 means
2^2 = 4 pages.
=head1 SEE ALSO
See C<Documentation/filesystems/proc.txt> in the Linux source tree for the
description of the buddyinfo file.
=head1 MAGIC MARKERS
#%# family=manual
#%# capabilities=autoconf
=head1 AUTHOR
Gábor Gombás <gombasg@sztaki.hu>
=head1 LICENSE
GPLv2 or later
=cut
use strict;
use Munin::Plugin;
use POSIX;
use Carp;
need_multigraph();
if ($ARGV[0] and $ARGV[0] eq 'autoconf') {
if (-f "/proc/buddyinfo") {
print "yes\n";
}
else {
print "no (/proc/buddyinfo is missing)\n";
}
exit 0;
}
# The most common page size is 4k, but it is not universal
my $pagesize = POSIX::sysconf(&POSIX::_SC_PAGESIZE) / 1024;
my $zones = {};
open(FH, '< /proc/buddyinfo')
or croak "Failed to open '/proc/buddyinfo': $!";
while (my $line = <FH>) {
chomp $line;
$line =~ m/Node (\d+), zone\s+(\S+)\s+(\S.*)$/;
my $name = "Node $1, zone $2";
my @cnt = split(/ +/, $3);
$zones->{$name} = \@cnt;
}
close FH;
my $totals = [];
foreach my $zone (keys %$zones) {
for my $i (0 .. $#{$zones->{$zone}}) {
$totals->[$i] += $zones->{$zone}->[$i]
}
}
sub do_config {
print "multigraph buddyinfo\n";
print "graph_title Memory fragmentation\n";
print "graph_args --base 1024 --lower-limit 0\n";
print "graph_vlabel pages free\n";
print "graph_category system\n";
print "graph_info This graph shows the number of free pages of different size\n";
print "graph_order " . join(' ', map { "order$_" } (0 .. $#{$totals})) . "\n";
for my $i (0 .. $#{$totals}) {
print "order$i.label Order $i\n";
print "order$i.info Number of order $i (" . ($pagesize * 2 ** $i) . " KiB) pages\n";
print "order$i.type GAUGE\n";
print "order$i.draw LINE2\n";
print "order$i.min 0\n";
}
for my $zone (sort keys %$zones) {
my $zoneid = $zone;
$zoneid = clean_fieldname($zone);
print "multigraph buddyinfo.$zoneid\n";
print "graph_title Memory fragmentation in $zone\n";
print "graph_args --base 1024 --lower-limit 0\n";
print "graph_vlabel pages free\n";
print "graph_category system\n";
print "graph_info This graph shows the number of free pages in $zone\n";
print "graph_order " .
join(' ', map { "order$_" } (0 .. $#{$zones->{$zone}})) . "\n";
for my $i (0 .. $#{$zones->{$zone}}) {
print "order$i.label Order $i\n";
print "order$i.info Number of order $i (" .
($pagesize * 2 ** $i) . " KiB) pages\n";
print "order$i.type GAUGE\n";
print "order$i.draw LINE2\n";
print "order$i.min 0\n";
}
}
}
sub do_fetch {
print "multigraph buddyinfo\n";
for my $i (0 .. $#{$totals}) {
print "order$i.value " . $totals->[$i] . "\n";
}
for my $zone (sort keys %$zones) {
my $zoneid = $zone;
$zoneid =~ tr/ ,/__/;
print "multigraph buddyinfo.$zoneid\n";
for my $i (0 .. $#{$zones->{$zone}}) {
print "order$i.value " . $zones->{$zone}->[$i] . "\n";
}
}
}
if ($ARGV[0] and $ARGV[0] eq 'config') {
do_config();
exit 0;
}
do_fetch();
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