Set max count of zram devices to 28 for huge cpu systems

mkzram.service

@@ -1,6 +1,6 @@
 [Unit]
 Description=Enable compressed swap in memory using zram
-After=multi-user.target
+DefaultDependencies=no
 
 [Service]
 RemainAfterExit=yes

zram.spec

@@ -1,7 +1,7 @@
 Summary: Enable compressed swap in memory
 Name: zram
-Version: 1.0.0
-Release: 2%{?dist}
+Version: 1.0.1
+Release: 4%{?dist}
 License: GPLv2
 Group: System Environment/Daemons
 Source0: %{name}-%{version}.tar.bz2

zramstart

@@ -1,22 +1,45 @@
 #!/bin/sh
 
-num_cpus=$(nproc)
+set -o pipefail
+set -o nounset
+set -e
+set -x
+
+FACTOR=33
+COMP_ALGORITHM=lz4
+
+num_cpus=$(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=$((num_cpus - 1))
-FACTOR=33
+
 [ -f /etc/sysconfig/zram ] && source /etc/sysconfig/zram || true
-factor=$FACTOR # percentage
 
 memtotal=$(grep MemTotal /proc/meminfo | awk ' { print $2 } ')
-mem_by_cpu=$(($memtotal/$num_cpus*$factor/100*1024))
+mem_by_cpu=$(($memtotal/$num_cpus*${FACTOR}/100*1024))
+
+modprobe zram num_devices=$num_cpus
 
-modprobe -q zram num_devices=$num_cpus
+function getKernelMajorVersion() {
+	head -c 1 /proc/sys/kernel/osrelease
+}
 
 for i in $(seq 0 $last_cpu); do
-	#enable lz4 if that supported
-	grep -q lz4 /sys/block/zram$i/comp_algorithm && echo lz4 > /sys/block/zram$i/comp_algorithm
-	echo $mem_by_cpu > /sys/block/zram$i/disksize
-	mkswap /dev/zram$i
-	swapon -p 100 /dev/zram$i
+        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
+

zramstat

@@ -1,10 +1,20 @@
 #!/bin/sh
 
+function getKernelMajorVersion() {
+        head -c 1 /proc/sys/kernel/osrelease
+}
+
 ls /sys/block/zram* > /dev/null 2>&1 || exit 0
 
 for i in /sys/block/zram*; do
-	compr=$(< $i/compr_data_size)
-	orig=$(< $i/orig_data_size)
+	if [ $(getKernelMajorVersion) -gt 3 ]; then
+		compr=$(cat $i/mm_stat | awk '{ print $2 }')
+		orig=$(cat $i/mm_stat | awk '{ print $1 }')
+	else
+	        compr=$(< $i/compr_data_size)
+	        orig=$(< $i/orig_data_size)
+	fi
+
 	ratio=0
 	if [ $compr -gt 0 ]; then
 		ratio=$(echo "scale=2; $orig*100/$compr" | bc -q)

zramstop

@@ -1,10 +1,23 @@
 #!/bin/sh
 
+set -o pipefail
+set -o nounset
+set -e
+set -x
+
+function getKernelMajorVersion() {
+        head -c 1 /proc/sys/kernel/osrelease
+}
+
 for i in $(grep '^/dev/zram' /proc/swaps | awk '{ print $1 }'); do
-	swapoff "$i"
+	swapoff -v "$i"
+	n=$(echo $i |  sed 's/[^0-9]//g')
+	echo 1 > /sys/block/zram${n}/reset
+	if [ $(getKernelMajorVersion) -gt 3 ]; then
+		echo $n > /sys/class/zram-control/hot_remove
+	fi
 done
 
-if grep -q "^zram " /proc/modules; then
-	sleep 1
-	rmmod zram
+if [ $(getKernelMajorVersion) -le 3 ]; then
+	grep zram /proc/modules && rmmod -v zram
 fi