#!/usr/bin/perl
use File::Slurp;
use POSIX;
use strict;
use warnings;
File::Slurp::write_file('/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor', 'schedutil');
my $available_frequencies = File::Slurp::read_file('/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies', { chomp => 1 });
$available_frequencies = [ split(/\s+/, $available_frequencies) ];
while (1) {
my $temp = File::Slurp::read_file('/sys/class/thermal/thermal_zone0/temp', { chomp => 1, err_mode => 'quiet' });
my $freq = $available_frequencies->[0];
for (my $i = 0; $i < scalar(@{$available_frequencies}); $i++) {
$freq = $available_frequencies->[$i] if $temp < (75 - $i) * 1000;
}
print sprintf("%s %s temp=%.1f°C max_freq=%iMHz\n", $0, POSIX::strftime('%Y-%m-%dT%H:%M:%S', gmtime), $temp/1000, $freq/1000);
File::Slurp::write_file('/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq', $freq);
sleep 6;
}
