File cpufreq-test.pl of Package powersave

#!/usr/bin/perl -w
#
# (C) Stefan Seyfried 2007, released under GPL v2.
#
# test script to test if the dynamic cpufreq scaling is working
# needs the cpufrequtils package
#
# note that this is just a very simple and basic test if the cpu frequency
# is changing at all, it does not test every aspect of freqency scaling.

$cpufreq_info = "/usr/bin/cpufreq-info";
$|=1;
$err = 0;

if (! -e $cpufreq_info) {
	print "$cpufreq_info not found. Please make sure that the\n";
	print "cpufrequtils package is installed.\n\n";
	exit 1;
}

print "Examining the system:\n";
print "=====================\n";
$i = 0;
while (1) {
	$limits = `$cpufreq_info -c $i -l`;
	last if ($limits eq '');
	($min[$i], $max[$i]) = split(/\s/,$limits);
	print "CPU$i Minimum frequency: $min[$i], maximum frequency: $max[$i]\n";
	$i++;
}

$numcpus = $i;

if ($numcpus == 0) {
	print "\n";
	print "No freqency scaling capable CPUs found.\n";
	print "This is what cpufreq-info tells about your machine:\n";
	print "===================================================\n\n";
	system("$cpufreq_info");
	print "\n";
	exit 1;
}

print "$numcpus CPU".(($numcpus == 1)?"":"s")." found.\n\n";
print "Starting the test:\n";

if (system("powersave -A") != 0) {
	print "\n";
	print "WARNING: ==============================================================\n";
	print "could not set powersave policy to 'dynamic'. Trying to continue anyway.\n";
	print "=======================================================================\n\n";
	$err++;
}

print "Waiting for cpu load to go down.\n";
$retry = 1;
while ($retry) {
	$retry = 0;
	@cur = get_current_freqs();
	for ($i = 0; $i < $numcpus; $i++) {
		if ($cur[$i] != $min[$i]) {
			print "info: cpu$i frequency is not at minimum, waiting";
			while ($cur[$i] != $min[$i]) {
				print ".";
				sleep 1;
				$cur[$i] = get_current_freq($i);
			}
			print "\n";
			$retry = 1;
		}
	}
}

$SIG{'CHLD'} = 'IGNORE';

print "Starting CPU load generation (one instance per CPU)\n";
for ($i = 0; $i < $numcpus; $i++) {
	if (($pid = fork()) == -1) {
		print "ERROR: could not fork. This must not happen.\n";
		exit 1;
	} elsif ($pid == 0) {
		alarm (5);
		$SIG{'ALRM'} = sub { exit; };
		print " ...instance $i";
		while (1){};
		exit;
	}
}
sleep 1;
print " ...done.\n\n";
sleep 1;

print "Getting current frequenc".(($numcpus == 1)?"y":"ies")." (under load):\n";
@full = get_current_freqs();
for ($i = 0; $i < $numcpus; $i++) {
	print "  Current CPU$i frequency is: $full[$i]";
	if ($full[$i] != $max[$i]) {
		print "  WARNING! NOT FULL SPEED!";
		$err++;
	}
	print "\n";
}

print "\nWaiting for load generators to terminate...";
sleep 5;
print "done.\n\n";

print "Getting current frequenc".(($numcpus == 1)?"y":"ies")." (no load):\n";
@cur = get_current_freqs();
for ($i = 0; $i < $numcpus; $i++) {
	print "  Current CPU$i frequency is: $cur[$i]";
	if ($cur[$i] != $min[$i]) {
		print "  WARNING! NOT MINIMUM SPEED!";
		$err++;
	}
	print "\n";
}

print "\n\n";
print "Executive summary:\n";
print "==================\n\n";
if ($err == 0) {
	print "Everything looks OK.\n\n";
	exit 0;
} else {
	print "$err Warnings, please check the output above.\n\n";
}

exit 1;

sub get_current_freqs {
	my $i; my @ret; my $tmp;
	for ($i=0; $i < $numcpus; $i++) {
		$ret[$i] = get_current_freq($i);
	}
	return @ret;
}

sub get_current_freq {
	my $i = $_[0];
	my $ret = `$cpufreq_info -c $i -f`;
	chomp $ret;
	return $ret + 0;
}