Add zswapstats script

.bin/zswapstats

@@ -0,0 +1,86 @@
+#!/bin/bash
+# Source: https://wiki.tnonline.net/w/Blog/Zswap_statistics
+
+# System page size
+page_size=$(getconf PAGESIZE)
+
+# Location of zswap settings
+settings_dir="/sys/module/zswap/parameters"
+
+# Location of zswap statistics
+statistics_dir="/sys/kernel/debug/zswap"
+
+# Array of zswap settings
+settings=("accept_threshold_percent" "compressor" "enabled" "max_pool_percent")
+
+# Array of zswap statistics
+statistics=("pool_limit_hit" "pool_total_size" "reject_alloc_fail" "reject_compress_poor" "reject_kmemcache_fail" "reject_reclaim_fail" "stored_pages")
+
+# Declare an associative array to store zswap data
+declare -A zswap_data
+
+# Read zswap settings
+for setting in "${settings[@]}"; do
+	read -r value < "$settings_dir/$setting"
+	zswap_data["$setting"]=$value
+done
+
+# Read zswap statistics
+for stat in "${statistics[@]}"; do
+	read -r value < "$statistics_dir/$stat"
+	zswap_data["$stat"]=$value
+done
+
+# Determine the maximum length of keys (setting/statistic names)
+max_length=0
+for key in "${!zswap_data[@]}"; do
+	if [ ${#key} -gt $max_length ]; then
+		max_length=${#key}
+	fi
+done
+((width = max_length + 4))
+
+# Calculate the total size and compressed size in MiB
+total_size=$((zswap_data["stored_pages"] * page_size / (1024 * 1024) ))
+compressed_size=$((zswap_data["pool_total_size"] / (1024 * 1024) ))
+
+# Calculate the compression ratio
+if [ "${zswap_data["stored_pages"]}" -ne 0 ]; then
+	compression_ratio=$(bc <<< "scale=2; (${zswap_data["stored_pages"]} * $page_size / ${zswap_data["pool_total_size"]})")
+else
+	compression_ratio=0
+fi
+
+
+# Output the zswap settings
+printf "========\n"
+printf "SETTINGS"
+printf "\n========\n"
+for key in "${settings[@]}"; do
+    # Get the value from the associative array
+    value=${zswap_data["$key"]}
+
+    # Output the key (name) and value in columns
+    printf "%-*s%s\n" "$width" "$key" "$value"
+done
+
+# Output the zswap data
+printf "\n========\n"
+printf "VALUES"
+printf "\n========\n"
+for key in "${statistics[@]}"; do
+    # Get the value from the associative array
+    value=${zswap_data["$key"]}
+
+    # Output the key (name) and value in columns
+    printf "%-*s%s\n" "$width" "$key" "$value"
+done
+
+# Output the total size, compressed size, and compression ratio
+printf "\n========\n"
+printf "SUMMARY"
+printf "\n========\n"
+printf "%-*s%s MiB\n" "$width" "Total Size:"        "$total_size"
+printf "%-*s%s MiB\n" "$width" "Compressed Size:"   "$compressed_size"
+printf "%-*s%s\n"     "$width" "Compression Ratio:" "$compression_ratio"
+