Auto memory reclaim shell script

autoMemoryReclaim.sh

#!/bin/bash

# Put under /etc/autoMemoryReclaim.sh

# set variables at the top
low_cpu_usage=50  # Note: We work with integer percentages (e.g., 50%)
idle_time=2       # Minutes
cached_memory_limit=1000  # MB
percent_memory_to_reclaim=5  # Percentage as an integer
wait_period=3

# function to check if user is idle
is_idle() {
  loadavg=$(cat /proc/loadavg)
  load1=$(echo "$loadavg" | awk '{print $1}')
  load5=$(echo "$loadavg" | awk '{print $2}')
  load15=$(echo "$loadavg" | awk '{print $3}')
  
  if (( $(echo "$load15 < $low_cpu_usage" | bc -l) )) && (( $(echo "$load1 < $low_cpu_usage" | bc -l) )) && (( $(echo "$load5 < $low_cpu_usage" | bc -l) )); then
    return 0
  else
    return 1
  fi
}

# function to get cached memory
get_cached_memory() {
  mem_info=$(free -m | grep "^Mem:" | awk '{print $6}')
  echo "$mem_info"
}

# initialize state
state="waiting_to_be_idle"
idle_counter=0

while true; do
  if [[ $state == "waiting_to_be_idle" ]]; then
     if is_idle; then
      ((idle_counter++))
      echo "User is idle for $idle_counter minutes"
      if ((idle_counter >= idle_time)); then
        state="reclaiming_memory"
        echo "User has been idle for $idle_time minutes, now moving to reclaiming memory state"
      fi
    else
      idle_counter=0
      echo "User is not idle"
    fi
  elif [[ $state == "reclaiming_memory" ]]; then
    if is_idle; then
      mem_cached=$(get_cached_memory)
      echo "Mem cached: $mem_cached ! and $cached_memory_limit"
      if [[ "$mem_cached" -lt "$cached_memory_limit" ]]; then
        state="waiting_to_be_idle"
        echo "Cached memory limit of $cached_memory_limit MB reached, now moving back to waiting to be idle state"
      else
        mem_total=$(awk '/MemTotal/ {print int($2/1024)}' /proc/meminfo)
        mem_to_reclaim=$((mem_total * percent_memory_to_reclaim / 100))
        echo "Reclaiming $mem_to_reclaim MB of memory"
        echo "${mem_to_reclaim}M" | sudo tee -a /sys/fs/cgroup/unified/memory.reclaim
        sleep $wait_period
      fi
    else
      state="waiting_to_be_idle"
      echo "User is not idle, now moving back to waiting to be idle state"
    fi
  fi

  # check every minute
  sleep $wait_period
done

startLogging.sh

#!/bin/bash

# Used if you want to log your memory values over time to see the behaviour.

csv_file="output.csv"

# Create the CSV file if it doesn't exist
if [[ ! -f "$csv_file" ]]; then
    echo "Seconds Since Starting,Used Memory (MB),Cached Memory (MB),Free Memory (MB),1 Min CPU,5 Min CPU,15 Min CPU,Total Memory Available (MB),Total Memory Used by vmmemwsl (MB)" > "$csv_file"
fi

# Define conversion constants
MB=$((1024 * 1024))

# Start time
start_time=$(date +%s)

while true; do
    echo "Collecting system information..."

    # Get system memory information in bytes
    mem_info=$(free -b | grep "Mem:")
    used_mem=$(echo "$mem_info" | awk '{print $3}')
    cached_mem=$(echo "$mem_info" | awk '{print $6}')
    free_mem=$(echo "$mem_info" | awk '{print $4}')

    # Convert memory values to megabytes
    used_mem_mb=$((used_mem / MB))
    cached_mem_mb=$((cached_mem / MB))
    free_mem_mb=$((free_mem / MB))

    # Get CPU load averages
    load_1min=$(cat /proc/loadavg | awk '{print $1}')
    load_5min=$(cat /proc/loadavg | awk '{print $2}')
    load_15min=$(cat /proc/loadavg | awk '{print $3}')

    # Get total memory available in Windows
    echo "Fetching total memory available in Windows..."
    total_mem_avail=$(powershell.exe "(Get-CimInstance -ClassName Win32_OperatingSystem).FreePhysicalMemory" | sed 's/\r$//')

    # Convert total memory available to megabytes
    total_mem_avail_mb=$((total_mem_avail / 1024))

    # Get total memory used by vmmemwsl process
    echo "Fetching total memory used by vmmemwsl process..."
    total_mem_vmmem=$(powershell.exe "(Get-Process -Name vmmemwsl | Measure-Object -Property WS -Sum).Sum" | sed 's/\r$//')

    # Convert total memory used by vmmemwsl to megabytes
    total_mem_vmmem_mb=$((total_mem_vmmem / MB))

    # Calculate seconds since starting
    current_time=$(date +%s)
    seconds_since_start=$((current_time - start_time))

    # Append the values to the CSV file
    echo "Appending system information to $csv_file..."
    echo "$seconds_since_start,$used_mem_mb,$cached_mem_mb,$free_mem_mb,$load_1min,$load_5min,$load_15min,$total_mem_avail_mb,$total_mem_vmmem_mb" >> "$csv_file"

    echo "System information collected and logged successfully."

    # Wait for 1 second before the next iteration
    echo "Waiting for the next iteration..."
    sleep 10
done

wsl.conf

# Make sure your /etc/wsl.conf file looks like this to have the script auto start on start up of your WSL distro
[boot]
command=/etc/autoMemoryReclaim.sh