From 521eafacb254ac5abcbfaff67de77d19245c8828 Mon Sep 17 00:00:00 2001
From: Kirill Berezin <enelar@exsul.net>
Date: Sat, 5 Mar 2016 08:52:18 +0300
Subject: [PATCH 1/3] Workstation tuning params

---
 zramstart | 29 +++++++++++++++++------------
 zramstat  | 33 ++++++++++++++++++++++++++-------
 2 files changed, 43 insertions(+), 19 deletions(-)

diff --git a/zramstart b/zramstart
index 7df5429..b2c4469 100755
--- a/zramstart
+++ b/zramstart
@@ -3,20 +3,25 @@
 num_cpus=$(grep -c processor /proc/cpuinfo)
 [ "$num_cpus" != 0 ] || num_cpus=1
 
-last_cpu=$((num_cpus - 1))
-FACTOR=33
+threads=$((num_cpus * 4))
+last_thread=$((threads - 1))
+FACTOR=200
+
 [ -f /etc/sysconfig/zram ] && source /etc/sysconfig/zram || true
 factor=$FACTOR # percentage
 
 memtotal=$(grep MemTotal /proc/meminfo | awk ' { print $2 } ')
-mem_by_cpu=$(($memtotal/$num_cpus*$factor/100*1024))
-
-modprobe -q zram num_devices=$num_cpus
-
-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
+mem_by_cpu=$(($memtotal/$threads*$factor/100*1024))
+modprobe -q zram num_devices=$threads
+for i in $(seq 0 $last_thread); do
+  #enable lz4 if that supported
+  grep -q lz4 /sys/block/zram$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
 done
+
+echo 100 > /proc/sys/vm/swappiness
+echo 15 > /proc/sys/vm/dirty_ratio
+echo 3 > /proc/sys/vm/dirty_background_ratio
+echo 100000 > /proc/sys/vm/vfs_cache_pressure
diff --git a/zramstat b/zramstat
index 66274c0..13c8b1f 100755
--- a/zramstat
+++ b/zramstat
@@ -2,12 +2,31 @@
 
 ls /sys/block/zram* > /dev/null 2>&1 || exit 0
 
+sum_compr=0
+sum_orig=0
+
+while [ 1 ]; do
+
 for i in /sys/block/zram*; do
-	compr=$(< $i/compr_data_size)
-	orig=$(< $i/orig_data_size)
-	ratio=0
-	if [ $compr -gt 0 ]; then
-		ratio=$(echo "scale=2; $orig*100/$compr" | bc -q)
-	fi
-	echo -e "/dev/${i/*\/}:\t$ratio% ($orig -> $compr)"
+  compr=$(< $i/compr_data_size)
+  orig=$(< $i/orig_data_size)
+  sum_compr=$((sum_compr+compr))
+  sum_orig=$((sum_orig+orig))
+  ratio=0
+  if [ $compr -gt 0 ]; then
+    ratio=$(echo "scale=2; $orig*100/$compr" | bc -q)
+  fi
+# echo -e "/dev/${i/*\/}:\t$ratio% ($orig -> $compr)"
+done
+
+ratio=0
+if [ $sum_compr -gt 0 ]; then
+  ratio=$(echo "scale=2; $sum_orig*100/$sum_compr" | bc -q)
+fi
+sum_orig=$((sum_orig/1024/1024))
+sum_compr=$((sum_compr/1024/1024))
+diff=$((sum_orig-sum_compr))
+
+echo -ne "\t GAINED $diff MB by using $sum_compr MB\r    "
+sleep 1
 done

From 02c67f043a8fabf226bf81268d713cfc90a2a2d5 Mon Sep 17 00:00:00 2001
From: Kirill Berezin <enelar@exsul.net>
Date: Wed, 7 Dec 2016 20:13:20 +0300
Subject: [PATCH 2/3] Fix IO hung / freeze system

After several months of experience, i noticed that huge IO operations will hung system.
---
 zramstart | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/zramstart b/zramstart
index b2c4469..351ccd7 100755
--- a/zramstart
+++ b/zramstart
@@ -21,7 +21,11 @@ for i in $(seq 0 $last_thread); do
   swapon -p 100 /dev/zram$i
 done
 
-echo 100 > /proc/sys/vm/swappiness
-echo 15 > /proc/sys/vm/dirty_ratio
-echo 3 > /proc/sys/vm/dirty_background_ratio
-echo 100000 > /proc/sys/vm/vfs_cache_pressure
+# vm.vfs_cache_pressure=50
+# vm.dirty_ratio=30
+# vm.dirty_background_ratio=20
+
+# ON SSD
+# vm.swappiness=5
+# ON HDD
+# vm.swappiness=99

From 4e075a915a1a46f6d3871f60087041b54f74ee5e Mon Sep 17 00:00:00 2001
From: Kirill Berezin <enelar@exsul.net>
Date: Wed, 7 Dec 2016 20:18:29 +0300
Subject: [PATCH 3/3] Also don't forget prioritize kswap0

---
 zramstart | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/zramstart b/zramstart
index 351ccd7..9804655 100755
--- a/zramstart
+++ b/zramstart
@@ -29,3 +29,6 @@ done
 # vm.swappiness=5
 # ON HDD
 # vm.swappiness=99
+
+# if you having SSD, you may try class 1 (realtime)
+# ionice -c 2 -p `pgrep kswapd0`