LapUtil: Custom Linux Governor for Laptops

LapUtil is a custom CPU frequency governor designed for laptops to extend battery life. It's based on the proven conservative governor but optimized with a more aggressive, real-time approach to frequency scaling.

Key Features

• Based on conservative: It utilizes the stable, time-tested logic of the conservative governor, which scales CPU frequency incrementally in response to load changes.
• Optimized for Battery Saving: LapUtil is specifically tailored for low-power environments, aiming to transition to lower frequencies more quickly when the CPU is under light load.
• Aggressive, Real-Time Frequency Scaling: It measures CPU load in real time and aggressively scales down to the minimum frequency when the load is very low. This balances performance by minimizing power consumption without noticeable impact during low-demand tasks.

Smart Features

Adapted Load Smoothing

The governor calculates a smoothed load value using an Exponential Moving Average (EMA) to prevent unnecessary frequency jitter from minor load fluctuations. The smoothing factor (alpha) is not fixed; it is dynamically adjusted based on load volatility.

• High Volatility: When the CPU load changes rapidly, alpha increases, making the governor highly responsive.

• Low Volatility: During steady workloads (like video playback), alpha decreases, prioritizing stability and power efficiency.

• Dynamic EMA Alpha using Load Delta: EMA Alpha is automatically calculated via CPU Load delta.

Battery Awareness

Battery Awareness

laputil automatically detects whether the system is running on AC power or battery. It then applies a dynamic adjustment to the powersave_bias tunable:

• On AC Power: The bias is shifted towards performance.
• On Battery: The bias is shifted towards power saving.

This allows the governor to seamlessly transition between performance-focused and efficiency-focused modes without user intervention.

Install/Update

Installation

su
./scripts/generate_ac_headers.sh
./install.sh

Update

su
./scripts/generate_ac_headers.sh
./update.sh

For Intel Chips(Required)

Add intel_pstate=passive to GRUB_CMDLINE_LINUX_DEFAULT.

For Intel Meteor Lake Chips(Required)

patch -p1 < lp-e.patch

Example

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_pstate=passive"

Modprobe Command

sudo modprobe cpufreq_laputil

Pernament Application

echo "cpufreq_laputil" | sudo tee /etc/modules-load.d/laputil.conf