Self-hosted GitHub Actions runners consume excessive CPU due to a busy-waiting sleep implementation that continuously checks the system clock instead of using efficient OS-level sleep functions. This can be fixed by replacing the runner's safe_sleep.sh script with a smarter version that prioritizes native sleep commands, falls back to bash built-ins like read with timeout, and only uses busy-waiting as a last resort. The solution significantly reduces idle CPU usage, though changes may be overwritten during automatic runner updates.
Table of contents
# The problem: Busy-waiting# The solution: A smarter sleep script# A word of caution# Additional resources884 Impressions