File zramstart of Package zram

#!/bin/bash
#set -x

# default factor of 1/4 of RAM
factor=4
# default priority is maximum priority
priority=32767
# use lz4 default algorithm on newer kernels
algorithm=lz4
# Anything new needs only one zram device
num_zdevs=1

[ -z "$FACTOR" ] || factor=$FACTOR
[ -z "$PRIORITY" ] || priority=$PRIORITY
[ -z "$ALGORITHM" ] || algorithm=$ALGORITHM
[ -z "$ZDEV_NUM" ] || num_zdevs=$ZDEV_NUM

# Calculate ZRAM size
mem_total=$(free -w |grep "^Mem" |awk '{printf("%d",$2)}')
zram_size=$((${mem_total} / ${factor} /1024))
mem_per_zdev=$((${zram_size} / ${num_zdevs}))

modprobe -r zram > /dev/null 2>&1 # fixes issue with multiple restarts
modprobe -q zram num_devices=${num_zdevs}
sleep 0.1 # fixes issue with multiple restarts

for i in $(seq 0 $((num_zdevs - 1))); do
  # Create ZRAM with the next free device
  zramdev=$(zramctl --find --algorithm ${algorithm} --size ${mem_per_zdev}MB 2>&1)
  # The above returns the device. Use it below
  if [ "$?" -eq 0 ]; then
    mkswap $zramdev
    swapon -p $priority $zramdev
  else
    echo -e "\n${zramdev}\n"
    exit 99
  fi
done

echo -e "\nActivated ZRAM swap device of ${zram_size} MB\n"