ushift

CLI tool to manage CPU performance scaling and power profiles

Install

• GH releases
• AUR https://aur.archlinux.org/packages/ushift

Quick start

Important

Changing scaling governor or P-state operation mode requires good understanding of how CPU driver scaling works on your system -> DYOR
In most cases keep kernel defaults.

Tip

ushift -h

Read current CPU scaling settings

# print help
ushift get -h

ushift get -g  # scaling governor
ushift get -e  # energy performance policy
ushift get -t  # turbo boost status

Set CPU scaling properties - root required

# print help
ushift set -h

# set the Energy Performance Policy (aka EPP/EPB)
sudo ushift set -e balance_performance
sudo ushift set -t yes  # enable turbo boost
sudo ushift set -d yes  # enable HWP dynamic boost (Intel only)

Get/set GPU scaling properties

# on Intel gpus with Xe driver
ushift get -x
sudo ushift set -x power_saving

# on AMD gpus
ushift get -r
sudo ushift set -r low

Apply a profile as defined in the config file (see below) - root required

sudo ushift perf  # performance
sudo ushift bal   # balance
sudo ushift sav   # save (low power)

Config file

Default: /etc/ushift/config.toml

## Battery device name to be used in /sys/class/power_supply/
## Only needed if multiple batteries are present, otherwise it is
## detected automatically
# battery_name = "BAT0"
## Battery polling interval in seconds
# battery_poll_rate = 30
## Battery % at which 'save' profile activates
# battery_low = 20

# See `ushift set -h` to get more information about the available
# options

[performance]
## If you understand the implications, you can override the kernel
## defaults for scaling governor and P-state operation mode
# governor = "powersave"
# pstate_op_mode  = "active"
## Energy Performance Policy, possible values: performance,
## balance_performance, default, balance_power, power
energy_perf_policy = "balance_performance"
## Turbo boost
turbo_boost = true
## Intel HWP dynamic boost
# hwp_dyn_boost = true
## Intel gpus with Xe driver, possible values: base, power_saving
# intel_xe_power_profile = "base"
## AMD gpus DPM performance level, possible values:
## auto, low, high
# radeon_dpm_perf_level = "auto"

[balance]
energy_perf_policy = "balance_power"
turbo_boost = true
# hwp_dyn_boost = true
# intel_xe_power_profile = "base"
# radeon_dpm_perf_level = "auto"

# optional - if omitted, the 'save' profile is disabled
[save]
energy_perf_policy = "power"
turbo_boost = false
# hwp_dyn_boost = false
# intel_xe_power_profile = "power_saving"
# radeon_dpm_perf_level = "low"

Tip

Use -c <FILE> to specify a custom config file

Print the parsed config

ushift cfg

Laptop mode

In laptop mode ushift runs as a daemon and automatically switches profiles based on power state:

• performance - on AC power
• balance - on battery
• save - on battery below battery_low % (only if save is defined in config)

Note

CLI flags override equivalent config file properties.

Note

ushift uses libudev to detect AC power changes, so battery info doesn't need frequent polling. Default rate is 30 seconds (--poll-rate) so CPU footprint is minimal.

sudo ushift laptop

Important

Settings do not survive reboot. Use the systemd services below.

Systemd services

Two services are provided.

ushift-laptop.service - laptop daemon, switches profiles automatically:

sudo systemctl enable --now ushift-laptop.service

ushift-perf.service - oneshot, applies the performance profile at boot (desktop/server):

sudo systemctl enable --now ushift-perf.service

To use a custom config file, override the service:

ExecStart=/usr/bin/ushift laptop --config /path/to/config.toml

Example use cases

Laptop with auto-switch profiles, power saving below 15% battery

Enable/start ushift-laptop.service with config:

battery_low = 15 # %

# on AC
[performance]
energy_perf_policy = "balance_performance"
turbo_boost = true
hwp_dyn_boost = true # Intel only

# on battery
[balance]
energy_perf_policy = "balance_power"
turbo_boost = true
hwp_dyn_boost = false

# on battery powersave mode
[save]
energy_perf_policy = "power"
turbo_boost = false
hwp_dyn_boost = false

Desktop/server perf profile applied at boot

Enable/start ushift-perf.service with config:

[performance]
energy_perf_policy = "balance_performance"
turbo_boost = true
hwp_dyn_boost = true # Intel only

Oneshot tweak/profile switch

sudo ushift set -e power  # set Energy Performance Policy to 'power'
sudo ushift sav  # switch to (power)save profile

Implementation details

ushift is a lightweight wrapper around sysfs: reads and writes the kernel's cpufreq/intel_pstate/amd_pstate/DRM files directly. No background process except in laptop mode.

Laptop mode detects AC changes via libudev netlink uevents combined with ppoll, blocking efficiently instead of busy-polling. Battery level is only checked on a timer when a save profile is configured.

References

• https://docs.kernel.org/admin-guide/pm/cpufreq.html
• https://docs.kernel.org/admin-guide/pm/intel_pstate.html
• https://docs.kernel.org/admin-guide/pm/amd-pstate.html
• https://docs.kernel.org/gpu/xe/index.html
• https://docs.kernel.org/gpu/amdgpu/thermal.html
• https://wiki.archlinux.org/title/CPU_frequency_scaling
• https://github.com/linrunner/TLP

License

Apache License 2.0 WITH Commons-Clause-1.0