my experiment dynamic zram & support files

zram-dynamic.sh

#!/bin/bash

# === Konfigurasi Agresif ===
THRESHOLD_NODE=75      
THRESHOLD_FREE_ALL=45  
ADD_SIZE="1G"          
MAX_ZRAM=8             
BASE_DEVICE="zram0"    
BASE_PRIO=100          

log() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') $*"
}

# Menggunakan file sementara atau teknik variable injection agar data tidak hilang
get_zram_stats() {
    local t_used=0
    local t_size=0
    
    # Mengambil data langsung dari swapon tanpa pipe berlebih agar lebih stabil
    while read -r line; do
        # Hanya ambil baris yang mengandung /dev/zram
        if [[ "$line" == *"/dev/zram"* ]]; then
            local u=$(echo "$line" | awk '{print $2}')
            local s=$(echo "$line" | awk '{print $3}')
            t_used=$(( t_used + u ))
            t_size=$(( t_size + s ))
        fi
    done < <(swapon --show=NAME,USED,SIZE --noheadings --bytes)
    
    echo "$t_used $t_size"
}

get_zram_global_pct() {
    local stats=$(get_zram_stats)
    local used=$(echo $stats | awk '{print $1}')
    local size=$(echo $stats | awk '{print $2}')
    
    if [[ $size -gt 0 ]]; then
        # Bagi 1024 agar tidak overflow saat dikali 100
        echo $(( ( (used / 1024) * 100) / (size / 1024) ))
    else
        echo 0
    fi
}

get_node_by_rank() {
    local rank=$1
    swapon --show=NAME,USED,SIZE --noheadings --bytes | grep "^/dev/zram" | sort -V | tail -n $((rank+1)) | head -n 1
}

get_zram_count() {
    zramctl --noheadings | grep -c "^/dev/zram"
}

log_system_info() {
    local ram_total ram_available ram_used ram_percent
    ram_total=$(awk '/MemTotal/ {print $2}' /proc/meminfo)
    ram_available=$(awk '/MemAvailable/ {print $2}' /proc/meminfo)
    ram_used=$(( ram_total - ram_available ))
    ram_percent=$(( ram_used * 100 / ram_total ))

    local stats=$(get_zram_stats)
    local z_used_b=$(echo $stats | awk '{print $1}')
    local z_size_b=$(echo $stats | awk '{print $2}')
    local g_pct=$(get_zram_global_pct)

    log "--- System Info ---"
    log "RAM   : $(( ram_used / 1024 ))MB used / $(( ram_total / 1024 ))MB total (${ram_percent}%)"
    log "ZRAM  : $(( z_used_b / 1024 / 1024 ))MB used / $(( z_size_b / 1024 / 1024 ))MB total (${g_pct}%)"

    log "--- Per Device ---"
    zramctl --noheadings --output NAME,ALGORITHM | sort -V | while read -r dev algo; do
        local swap_info=$(swapon --show=NAME,USED,SIZE,PRIO --noheadings --bytes | grep -w "$dev")
        if [[ -n "$swap_info" ]]; then
            local u_b=$(echo "$swap_info" | awk '{print $2}')
            local s_b=$(echo "$swap_info" | awk '{print $3}')
            local prio=$(echo "$swap_info" | awk '{print $4}')
            local d_pct=0
            [[ $s_b -gt 0 ]] && d_pct=$(( ( (u_b/1024) * 100) / (s_b/1024) ))
            log "$dev : $(( u_b / 1024 / 1024 ))MB / $(( s_b / 1024 / 1024 ))MB (${d_pct}%) [Prio: $prio] [$algo]"
        fi
    done
    log "-------------------"
}

add_zram_node() {
    local count=$(get_zram_count)
    [[ $count -ge $MAX_ZRAM ]] && return
    local prio=$(( BASE_PRIO - count ))
    
    local zombie=$(zramctl --noheadings --output NAME | while read -r z; do 
        if ! swapon --show=NAME --noheadings | grep -q "$z"; then echo "$z"; break; fi
    done)

    if [[ -n "$zombie" ]]; then
        mkswap "$zombie" > /dev/null 2>&1
        swapon "$zombie" --priority "$prio"
        log "RECOVERY: Activated zombie $zombie"
    else
        local new_dev=$(zramctl --find --size "$ADD_SIZE" --algorithm zstd)
        if [[ -n "$new_dev" ]]; then
            mkswap "$new_dev" > /dev/null 2>&1
            swapon "$new_dev" --priority "$prio"
            log "ACTION: Grow! Added $new_dev"
        fi
    fi
}

# === Main Execution ===
STATS=$(get_zram_stats)
GLOBAL_PCT=$(get_zram_global_pct)
COUNT=$(get_zram_count)

read -r LAST_NODE LAST_USED LAST_SIZE < <(get_node_by_rank 0)
LAST_PCT=0
if [[ -n "$LAST_SIZE" && $LAST_SIZE -gt 0 ]]; then
    LAST_PCT=$(( ( (LAST_USED/1024) * 100) / (LAST_SIZE/1024) ))
fi

log "CHECK : Last node ${LAST_NODE} is ${LAST_PCT}% full | Global ZRAM: ${GLOBAL_PCT}% | Active: ${COUNT}"

if [[ "$LAST_NODE" == "" || $LAST_PCT -ge $THRESHOLD_NODE ]]; then
    add_zram_node
    log_system_info
elif [[ $COUNT -gt 1 ]]; then
    if [[ $LAST_PCT -lt 10 && $GLOBAL_PCT -lt $THRESHOLD_FREE_ALL ]]; then
        log "ACTION: Shrink! Global usage safe (${GLOBAL_PCT}%) and node empty."
        swapoff "$LAST_NODE" && zramctl --reset "$LAST_NODE"
        log_system_info
    else
        log "STATUS: Stable (Global: ${GLOBAL_PCT}%, Last: ${LAST_PCT}%)."
        log_system_info
    fi
else
    log "STATUS: Stable."
    log_system_info
fi
log "=================================================="

zram-reset.sh

for dev in /dev/zram[1-9]*; do
    if [ -b "$dev" ]; then
        echo "Cleaning up $dev..."
        sudo swapoff "$dev" 2>/dev/null
        sudo zramctl --reset "$dev" 2>/dev/null
    fi
done