I'm trying to set the CPU governor to performance in 18.04, the problem is that it never survives reboots.
I've tried following these steps in an answer to this question How to set "Performance" instead of "Powersave" as default? but when I reboot the computer the CPU governor switches back to powersaver.
I've also tried creating a file called /etc/rc.local with the line:
cpupower frequency-set --governor performance
That also doesn't survive reboots.
How can I do this?
sudo apt-get install cpufrequtils
echo 'GOVERNOR="performance"' | sudo tee /etc/default/cpufrequtils
sudo systemctl disable ondemand
In /etc/rc.local put in these commands:
sleep 120
cpupower frequency-set --governor performance
For whatever reasons my Skylake Intel CPU always starts up in Performance mode and then switches to Powersave mode at the 1 minute mark automatically.
If you set the mode to Performance on startup it will be overridden around the 1 minute Up Time mark to Powersave mode.
In the GIF below, the 3000+ MHz CPU speed at start up appears near the top. The up time appears near the bottom. When up time hits about 1 minute you see CPU MHz drop off. :
Create this script in /usr/local/bin/watch-gov.sh:
#! /bin/bash
# NAME: watch-gov.sh
# PATH: /usr/local/bin
# DESC: Set governnor to performance and watch for change
# Ask Ubuntu question: https://askubuntu.com/questions/1021748/set-cpu-governor-to-performance-in-18-04/1084727#1084727
# CALL: called from `/etc/rc.local`
# DATE: Created Oct 18, 2018.
echo performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
last_gov=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor)
Uptime=$(uptime)
echo "watch-gov.sh: Set to performance at $Uptime " > /tmp/watch-gov.log
for ((i=0; i<300; i++)) ; do
curr_gov=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor)
if [ $last_gov != $curr_gov ] ; then
last_gov=$curr_gov
Uptime=$(uptime)
echo "watch-gov.sh: Current governor: $last_gov Uptime: $Uptime" >> \
/tmp/watch-gov.log
fi
sleep 1
done
Call the script in /etc/rc.local before the exit 0 command (explained in detail below).
One minute after logging in look at the output:
$ cat /tmp/watch-gov.log
watch-gov.sh: Set to performance at 17:50:09 up 0 min, 0 users, load average: 0.00, 0.00, 0.00
watch-gov.sh: Current governor: powersave Uptime: 17:51:09 up 1 min, 1 user, load average: 1.89, 0.62, 0.22
Confirmation from this answer states this 1 minute force to powersave governor is controlled by /etc/init.d/ondemand.
The simplest way to stay in Performance mode is to edit /etc/rc.local and insert these lines before the last line containing exit 0:
sleep 120 # Give CPU startup routines time to settle.
echo performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
Save the file and reboot.
If you insert the new lines after exit 0 it will never be executed.
To setup /etc/rc.local in 18.04 see: How to Enable /etc/rc.local with Systemd
Your machine will probably run 10 to 15 degrees C hotter.
You may need to remove other programs that change CPU frequency if they override your Performance settings in /etc/rc.local
Default Ubuntu kernel configurations are such that the performance CPU frequency scaling governor will be used during boot. The relevant section of the kernel configuration file ( /boot/config-4.15.0-36-generic , in this example) is:
#
# CPU Frequency scaling
#
CONFIG_CPU_FREQ=y
CONFIG_CPU_FREQ_GOV_ATTR_SET=y
CONFIG_CPU_FREQ_GOV_COMMON=y
CONFIG_CPU_FREQ_STAT=y
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
# CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL is not set
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_POWERSAVE=y
CONFIG_CPU_FREQ_GOV_USERSPACE=y
CONFIG_CPU_FREQ_GOV_ONDEMAND=y
CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
CONFIG_CPU_FREQ_GOV_SCHEDUTIL=y
#
# CPU frequency scaling drivers
#
CONFIG_X86_INTEL_PSTATE=y
CONFIG_X86_PCC_CPUFREQ=y
CONFIG_X86_ACPI_CPUFREQ=y
CONFIG_X86_ACPI_CPUFREQ_CPB=y
CONFIG_X86_POWERNOW_K8=y
CONFIG_X86_AMD_FREQ_SENSITIVITY=m
CONFIG_X86_SPEEDSTEP_CENTRINO=y
CONFIG_X86_P4_CLOCKMOD=m
But also by default during boot up the ondemand service is executed. It sleeps for 1 minutes and then changes the scaling governor to either interactive, ondemand or powersave, depending on availability. In turn availability depends on which CPU frequency scaling driver you are using. The code is (in multiple locations, search for ondemand):
#! /bin/sh
### BEGIN INIT INFO
# Provides: ondemand
# Required-Start: $remote_fs $all
# Required-Stop:
# Default-Start: 2 3 4 5
# Default-Stop:
# Short-Description: Set the CPU Frequency Scaling governor to "ondemand"
### END INIT INFO
# Don't run if we're going to start an Android LXC container:
[ ! -f /etc/init/lxc-android-config.conf ] || exit 0
PATH=/sbin:/usr/sbin:/bin:/usr/bin
. /lib/init/vars.sh
. /lib/lsb/init-functions
AVAILABLE="/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors"
DOWN_FACTOR="/sys/devices/system/cpu/cpufreq/ondemand/sampling_down_factor"
case "$1" in
start)
start-stop-daemon --start --background --exec /etc/init.d/ondemand -- background
;;
background)
sleep 60 # probably enough time for desktop login
[ -f $AVAILABLE ] || exit 0
read governors < $AVAILABLE
case $governors in
*interactive*)
GOVERNOR="interactive"
break
;;
*ondemand*)
GOVERNOR="ondemand"
case $(uname -m) in
ppc64*)
SAMPLING=100
;;
esac
break
;;
*powersave*)
GOVERNOR="powersave"
break
;;
*)
exit 0
;;
esac
for CPUFREQ in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
do
[ -f $CPUFREQ ] || continue
echo -n $GOVERNOR > $CPUFREQ
done
if [ -n "$SAMPLING" ] && [ -f $DOWN_FACTOR ]; then
echo -n $SAMPLING > $DOWN_FACTOR
fi
;;
restart|reload|force-reload)
echo "Error: argument '$1' not supported" >&2
exit 3
;;
stop)
;;
*)
echo "Usage: $0 start|stop" >&2
exit 3
;;
esac
Why is it called "ondemand", but it sets other governors (for example with the intel_pstate driver it will set the powersave governor)? Because this tool pre-dates the intel_pstate driver, back to a time when, by far, the dominant frequency scaling driver was the acpi-cpufreq driver, and "ondemand" was the preferred Ubuntu default governor.
So, one way to boot and stay using the performance CPU frequency scaling governor is to disable the service that changes away from it (which was also mentioned in another answer):
Before:
~$ systemctl list-units --all --type=service | grep ondemand
ondemand.service loaded inactive dead Set the CPU Frequency Scaling governor
~$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
ondemand
ondemand
Disable the service:
~$ sudo systemctl disable ondemand
Removed /etc/systemd/system/multi-user.target.wants/ondemand.service.
re-boot, then check again (being sure to wait a minute after the re-boot):
doug@s17:~$ systemctl list-units --all --type=service | grep ondemand
doug@s17:~$
doug@s17:~$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
performance
performance
Note: the examples in this answer are from a computer that uses the acpi-cpufreq CPU frequency scaling driver. If you are using the intel_pstate driver, with no ondemand governor, the powersave governor will be used by default.
Anticipated question: Why do my CPU frequencies scale, even when using the performance governor?
Answer: Modern processors scale the CPU frequency, even in performance mode and as a function of the depth of the idle state they go into. If you really want to lock the CPU frequency then disable all idle states deeper than 0. However, note that it will cost a huge huge amount of power.
Personally, and as mentioned in another answer, I use the performance governor or the powersave governor as a function of whatever work I am doing. My scripts are a little different:
$ cat set_cpu_performance
#! /bin/bash
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
for file in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do echo "performance" > $file; done
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
and:
$ cat set_cpu_powersave
#! /bin/bash
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
for file in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do echo "powersave" > $file; done
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
example usage (on a computer using the intel_pstate driver):
$ sudo ./set_cpu_performance
powersave
powersave
powersave
powersave
powersave
powersave
powersave
powersave
performance
performance
performance
performance
performance
performance
performance
performance
You'll first need to install cpufrequtils;
sudo apt install cpufrequtils
then, perform a restart and set cpufrequency to performance,
sudo cpufreq-set -g performance
Note: If you ran the above command without restarting, then you'd have to edit edit the file in /etc/init.d/cpufrequtils and change the line that says
GOVERNOR=ondemand
to
GOVERNOR=performance
then run;
sudo sh /etc/init.d/cpufrequtils start
it'd probably prompt you to restart your systemctl daemon, so do it like this;
sudo systemctl daemon-reload
this should do the work. then view your cpufrequency with;
cat /proc/cpuinfo | grep -i mhz
What I did was use the file /etc/rc.local
To help you find your paths, use:
find / -name scaling_governor
find / -name scaling_max_freq
This works for my setup, but you just need to edit it for your setup
I added to /etc/rc.local using nano:
# Set CPU Governor and Freq at boot up
echo "performance" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo 1500000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
echo 2000000 > /sys/devices/system/cpu/cpu4/cpufreq/scaling_max_freq
echo "performance" > /sys/devices/system/cpu/cpu4/cpufreq/scaling_governor
directly under the shebang line. Close nano with Ctrl-X and Y to save
Then for 18.04 (may not work on 16.04) on the command line run:
systemctl disable ondemand
Then on the command line - read /etc/rc.local and then reboot:
/etc/rc.local
reboot
if /etc/rc.local chokes and errors then make sure it's chmod +x /etc/rc.local
I am using this bash script to set the performance governor:
#!/bin/bash
sudo cpufreq-set --cpu 0 --governor performance
sudo cpufreq-set --cpu 1 --governor performance
sudo cpufreq-set --cpu 2 --governor performance
sudo cpufreq-set --cpu 3 --governor performance
sudo cpufreq-set --cpu 4 --governor performance
sudo cpufreq-set --cpu 5 --governor performance
sudo cpufreq-set --cpu 6 --governor performance
sudo cpufreq-set --cpu 7 --governor performance
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
Make is executable chmod +x cpu.sh and run at any time You need (ever right after every computer start/reboot).
I had a similar problem. In my case I wanted to set the governor to 'schedutil', but after a reboot I would always find the governor to be 'ondemand'. I read and did try most solutions presented here to no avail.
What did the trick for me, and I am using Ubuntu Mate 18.04.2 was finding the file:
/lib/systemd/set-cpufreq
editing it to insert the lines:
*schedutil*)
GOVERNOR="schedutil"
break
;;
so now the file reads:
#! /bin/sh
# Set the CPU Frequency Scaling governor to "ondemand"/"powersave" where available
set -eu
FIRSTCPU=`cut -f1 -d- /sys/devices/system/cpu/online`
AVAILABLE="/sys/devices/system/cpu/cpu$FIRSTCPU/cpufreq/scaling_available_governors"
DOWN_FACTOR="/sys/devices/system/cpu/cpufreq/ondemand/sampling_down_factor"
[ -f $AVAILABLE ] || exit 0
read governors < $AVAILABLE
case $governors in
*interactive*)
GOVERNOR="interactive"
break
;;
*schedutil*)
GOVERNOR="schedutil"
break
;;
*ondemand*)
GOVERNOR="ondemand"
case $(uname -m) in
ppc64*)
SAMPLING=100
;;
esac
break
;;
*powersave*)
GOVERNOR="powersave"
break
;;
*)
exit 0
;;
esac
[ -n "${GOVERNOR:-}" ] || exit 0
echo "Setting $GOVERNOR scheduler for all CPUs"
for CPUFREQ in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
do
[ -f $CPUFREQ ] || continue
echo -n $GOVERNOR > $CPUFREQ
done
if [ -n "${SAMPLING:-}" ] && [ -f $DOWN_FACTOR ]; then
echo -n $SAMPLING > $DOWN_FACTOR
fi.
and now when I boot my computer it starts with the 'schedutil' governor!
This has always worked perfectly for me:
echo performance | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor > /dev/null
You can check the current governor with: cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
sudo echo performance > /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor does not work at all. You must use tee.
A simple script to switch between powersave and performance mode. You can try with any of the 'wrmsr' commenting out one in below script. I don't know why, but writing 0 to register worked well for me.
#!/bin/bash
argument: powersave or performance
if [ $# != 1 ]
then
echo "You should specify CPU driver governor as argument!"
exit 1
fi
totalCPUs=$(lscpu | grep '^CPU(s):' | awk '{print $2}')
for (( cpuIndex=0; cpuIndex<$totalCPUs; cpuIndex++ ))
do
echo "Optimizing CPU $cpuIndex"
cpufreq-set -c $cpuIndex -g $1
done
if [ $1 == "performance" ]
then
modprobe msr
controlRegVal=$(rdmsr 0x1FC)
#wrmsr 0x1FC $controlRegVal
wrmsr 0x1FC 0
fi
exit 0
On Ubuntu 22.04 LTS, after setting GOVERNOR="performance" and disabling ondemand, I also had to restart cpufrequtils service to actually make it work:
sudo systemctl restart cpufrequtils.service
