Redirect CPU Cores for Gaming

gaming_cores_redirect.sh

#!/bin/bash

if [ "$#" -ne 1 ]; then
 echo "Forces games to run only on 'good' cores - e.g. first CCD on Ryzen CPUs."
 echo
 echo "Usage: $0 on/off/topo"
 echo
 echo "Turn On:           sudo $0 on"
 echo "Turn Off:          sudo $0 off"
 echo "Show cpu topology: sudo $0 topo"
 echo
 echo "Start by checking your CPU topology using 'topo' command."
 echo "Edit 'gaming_cores' and 'background_cores' variables in this script (lines 20 and 21) to select only the good cores (e.g. all real cores + SMT cores from CCD0)"
 echo "Start lutris/heroic/steam or have the game running already and then execute this script with 'on' command."
 echo "When done playing execute script with 'off' command."
 exit 1
fi

nice_value=-18
gaming_cores="0-5,12-17"      # Ryzen 5900X CCD0
background_cores="6-11,18-23" # Ryzen 5900X CCD1

function redirect_on {
  if ! [ -d /sys/fs/cgroup/tasks_redirect ]; then
    echo "Creating tasks_redirect group"
    mkdir /sys/fs/cgroup/tasks_redirect
  fi

  echo "Enable CPU-related controllers"
  echo "+cpu" >> /sys/fs/cgroup/tasks_redirect/cgroup.subtree_control
  echo "+cpuset" >> /sys/fs/cgroup/tasks_redirect/cgroup.subtree_control

  if ! [ -d /sys/fs/cgroup/tasks_redirect/background_cores ]; then
    echo "Creating background_cores child-group"
    mkdir /sys/fs/cgroup/tasks_redirect/background_cores
  fi

  echo "Assigning background cores to background_cores cpuset"
  echo "$background_cores" > /sys/fs/cgroup/tasks_redirect/background_cores/cpuset.cpus

  echo "Redirecting processes to background_cores cpuset"
  while read p; do
    echo $p > /sys/fs/cgroup/tasks_redirect/background_cores/cgroup.procs 2>&1
    if [ $? -eq 0 ]; then
      echo "Redirected PID $p"
    fi
  done < <(cat /sys/fs/cgroup/cgroup.procs | sort | uniq)

  if ! [ -d /sys/fs/cgroup/tasks_redirect/gaming_cores ]; then
    echo "Creating gaming_cores child-group"
    mkdir /sys/fs/cgroup/tasks_redirect/gaming_cores
  fi

  echo "Assigning gaming cores to gaming_cores cpuset"
  echo "$gaming_cores" > /sys/fs/cgroup/tasks_redirect/gaming_cores/cpuset.cpus

  echo "Setting nice=$nice_value for gaming_cores cpuset"
  echo "$nice_value" > /sys/fs/cgroup/tasks_redirect/gaming_cores/cpu.weight.nice

  echo "Redirecting game launchers to gaming_cores cpuset"
  pids=(`pgrep -f lutris`)
  pids+=(`pgrep heroic`)
  pids+=(`pgrep wine`)
  pids+=(`pgrep steam`)
  pids+=(`pgrep .exe`)
  for p in "${pids[@]}"
  do
    echo "Redirecting PID $p"
    echo $p > /sys/fs/cgroup/tasks_redirect/gaming_cores/cgroup.procs
  done
}

function redirect_off {
  if [ -d /sys/fs/cgroup/tasks_redirect/background_cores ]; then
    echo "Redirecting processes from background_cores back to main cpuset"
    while read p; do
      echo "Redirecting PID $p"
      echo $p > /sys/fs/cgroup/cgroup.procs
    done < <(cat /sys/fs/cgroup/tasks_redirect/background_cores/cgroup.procs | sort | uniq)
    rmdir /sys/fs/cgroup/tasks_redirect/background_cores
  fi

  if [ -d /sys/fs/cgroup/tasks_redirect/gaming_cores ]; then
    echo "Redirecting processes from gaming_cores back to main cpuset"
    while read p; do
      echo "Redirecting PID $p"
      echo $p > /sys/fs/cgroup/cgroup.procs
    done < <(cat /sys/fs/cgroup/tasks_redirect/gaming_cores/cgroup.procs | sort | uniq)
    rmdir /sys/fs/cgroup/tasks_redirect/gaming_cores
  fi  
}

if [ "${1,,}" = "on" ]; then
  redirect_on
  echo "REDIRECT ON"
elif [ "${1,,}" = "topo" ]; then
  lstopo  
else
  redirect_off
  echo "REDIRECT OFF"
fi