Optimization Guide

Getting maximum performance from rninja.

Parallelism

Use All Cores

rninja -j0  # Uses all CPU cores

Tune for Memory

Large builds may need limiting:

rninja -j8  # Limit to 8 jobs

Cache Optimization

Enable Caching

export RNINJA_CACHE_ENABLED=1

Use Fast Storage

export RNINJA_CACHE_DIR=/ssd/rninja-cache

Remote Cache for Teams

export RNINJA_CACHE_MODE=auto
export RNINJA_CACHE_REMOTE_SERVER=tcp://cache:9999

Build File Optimization

Declare All Dependencies

Undeclared dependencies cause cache misses.

Use Depfiles

Let the compiler report dependencies:

rule cc
  command = $cc -MD -MF $out.d -c $in -o $out
  depfile = $out.d

Avoid Non-Determinism

Remove timestamps and random values from builds.

Daemon Mode

Keep daemon running:

rninja  # Auto-spawns daemon

Subsequent builds are faster.

Profiling

Identify bottlenecks:

rninja --trace trace.json
# Open in chrome://tracing

Checklist

• Use all CPU cores (-j0)
• Enable caching
• Use SSD for cache
• Declare all dependencies
• Use depfiles
• Remove non-determinism
• Keep daemon running
• Profile slow builds