zramstart

#!/bin/sh

set -o pipefail
set -o nounset
set -e
set -x

FACTOR=33
COMP_ALGORITHM=lz4

num_cpus=$(grep -c processor /proc/cpuinfo)
num_cpus=$(($num_cpus<28?$num_cpus:28))

[ "$num_cpus" != 0 ] || num_cpus=1

max_comp_streams=$(($num_cpus>2?2:1))
last_cpu=$((num_cpus - 1))

[ -f /etc/sysconfig/zram ] && source /etc/sysconfig/zram || true

memtotal=$(grep MemTotal /proc/meminfo | awk ' { print $2 } ')
mem_by_cpu=$(($memtotal/$num_cpus*${FACTOR}/100*1024))

modprobe zram num_devices=$num_cpus

function getKernelMajorVersion() {
	head -c 1 /proc/sys/kernel/osrelease
}

for i in $(seq 0 $last_cpu); do
        n=$i
        if [ $(getKernelMajorVersion) -gt 3 ]; then
                n=$(cat /sys/class/zram-control/hot_add)
        fi
        block=/sys/block/zram${n}

        if [ "$(cat ${block}/disksize)" -eq 0 ] ; then
                [ -f ${block}/comp_algorithm ] && grep -q ${COMP_ALGORITHM} ${block}/comp_algorithm && echo ${COMP_ALGORITHM} > ${block}/comp_algorithm

                echo $mem_by_cpu > ${block}/disksize
                mkswap /dev/zram$n
                swapon -v -p 100 /dev/zram$n
        fi
done