From 17a3ee006a3ca6213049f7636e096d515eedc0b187c0fbf867d0bcf1b8ecf6bd Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Mon, 5 Sep 2022 11:01:40 +0000
Subject: [PATCH] Accepting request 1000767 from home:archerallstars

1. To disable multi-zRAM device creation (based on the number of CPU cores) in the original script, as it's deprecated, can cause some issues, and is unnecessary since kernel 4.7.

See https://bugzilla.suse.com/show_bug.cgi?id=1185928 and https://github.com/Nefelim4ag/systemd-swap/issues/176

2. To change the zRAM compression algorithm from "lzo-rle" to "zstd", as it yields the highest compression ratio, hence the fastest to complete the task. Both compression ratio and speed are better than "lzo-rle". Therefore, changing the compression algorithm to "zstd" will benefit zRAM usage.

See https://www.reddit.com/r/Fedora/comments/mzun99/new_zram_tuning_benchmarks/

OBS-URL: https://build.opensuse.org/request/show/1000767
OBS-URL: https://build.opensuse.org/package/show/filesystems/systemd-zram-service?expand=0&rev=6
---
 zramswapoff | 12 +-----------
 zramswapon  | 32 ++++++++------------------------
 2 files changed, 9 insertions(+), 35 deletions(-)

diff --git a/zramswapoff b/zramswapoff
index 552a27a..271222f 100644
--- a/zramswapoff
+++ b/zramswapoff
@@ -1,16 +1,6 @@
 #!/bin/bash
 
-# get the number of CPUs
-num_cpus=$(grep -c processor /proc/cpuinfo)
-
-# set decremented number of CPUs
-decr_num_cpus=$((num_cpus - 1))
-
 # Switching off swap
-for i in $(seq 0 $decr_num_cpus); do
-if [ "$(grep /dev/zram$i /proc/swaps)" != "" ]; then
-swapoff /dev/zram$i
-fi
-done
+swapoff /dev/zram0
 
 rmmod zram
diff --git a/zramswapon b/zramswapon
index 399a28d..09496b5 100644
--- a/zramswapon
+++ b/zramswapon
@@ -1,34 +1,18 @@
 #!/bin/bash
 
-# get the number of CPUs
-num_cpus=$(grep -c processor /proc/cpuinfo)
-# if something goes wrong, assume we have 1
-[ "$num_cpus" != 0 ] || num_cpus=1
-
-# set decremented number of CPUs
-decr_num_cpus=$((num_cpus - 1))
-
 # get the amount of memory in the machine
 mem_total_kb=$(grep MemTotal /proc/meminfo | grep -E --only-matching '[[:digit:]]+')
 mem_total=$((mem_total_kb * 1024))
 
-# load dependency modules
-#modprobe zram zram_num_devices=$num_cpus
-# Determine module parm
-mod_parm=$(modinfo zram |grep parm |tr -s " " |cut -f2 -d ":")
-modprobe zram $mod_parm=$num_cpus
+# load the dependency module
+modprobe zram
 
-# initialize the devices
-for i in $(seq 0 $decr_num_cpus); do
-echo $((mem_total / num_cpus)) > /sys/block/zram$i/disksize
-done
+# initialize the device with zstd compression algorithm
+echo zstd > /sys/block/zram0/comp_algorithm;
+echo $mem_total > /sys/block/zram0/disksize
 
-# Creating swap filesystems
-for i in $(seq 0 $decr_num_cpus); do
-mkswap /dev/zram$i
-done
+# Creating the swap filesystem
+mkswap /dev/zram0
 
 # Switch the swaps on
-for i in $(seq 0 $decr_num_cpus); do
-swapon -p 100 /dev/zram$i
-done
+swapon -p 100 /dev/zram0