kernel_build.sh

#!/bin/bash

# Create the results file with current date
current_dir=$(pwd "$0")
timestamp=$(date +%Y-%m-%d_%H-%M-%S)
results_file="${current_dir}/results_${timestamp}.txt"

collect_results() {
    # Get system information
    kernel_version=$(uname -r)
    cpu_name=$(cat /proc/cpuinfo | grep "model name" | uniq | cut -d ":" -f 2 | sed 's/^[ \t]*//')
    memory=$(free -h | awk 'NR==2{print $2}')
    cores=$(nproc)



    echo "System Information:" > "$results_file"
    echo "Kernel Version: $kernel_version" >> "$results_file"
    echo "CPU Name: $cpu_name" >> "$results_file"
    echo "Memory: $memory" >> "$results_file"
    echo "Number of Cores: $cores" >> "$results_file"
    echo "---------------------------------" >> "$results_file"
    echo "" >> "$results_file"

    # Append iteration times and average times to the results file
    echo "Iteration Times:" >> "$results_file"
    for ((i=0; i<num_iterations; i++))
    do
        echo "Iteration $((i+1)):" >> "$results_file"
        echo "Extraction Time: ${extract_times[$i]} seconds" >> "$results_file"
        echo "Build Time: ${build_times[$i]} seconds" >> "$results_file"
        echo "" >> "$results_file"
    done
    echo "---------------------------------" >> "$results_file"
    echo "Average Times:" >> "$results_file"
    echo "Average Extraction Time: ${average_extract_time} seconds" >> "$results_file"
    echo "Average Build Time: ${average_build_time} seconds" >> "$results_file"
    
}

# Number of iterations for compiling the kernel
declare -a extract_times
declare -a build_times

num_iterations=3

# Parse command-line options

while getopts ":n:" opt; do
    case $opt in
        n)
            num_iterations=$OPTARG
            echo "Using num_iterations = $OPTARG"
            ;;
        \?)
            echo "Invalid option: -$OPTARG. Usage: $0 -n <num_iterations>" >&2
            exit 1
            ;;
    esac
done

 # Download the kernel (if not downloaded already)
if [ ! -f "${current_dir}/linux-5.15.144.tar.xz" ]; then
    echo "Downloading ..." 
    wget https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.144.tar.xz -O ${current_dir}/linux-5.15.144.tar.xz
fi

for ((i=0; i<num_iterations; i++))
do
    # Start time after downloading
    extract_start_time=$(date +%s)
    tar -xvf ${current_dir}/linux-5.15.144.tar.xz &> /dev/null
    extract_end_time=$(date +%s)
    extract_duration=$((extract_end_time - extract_start_time))
    cd ${current_dir}/linux-5.15.144
    make defconfig &> /dev/null
    # Measure time to compile (excluding download and extraction times)
    compile_start_time=$(date +%s)
    make -j"$(nproc)" &> /dev/null
    compile_end_time=$(date +%s)
    compile_duration=$((compile_end_time - compile_start_time))

    # Delete build folder after each iteration
    rm -rf ${current_dir}/linux-5.15.144
    cd $current_dir

    # Record times for download, extraction, and build
    extract_times[$i]=$extract_duration
    build_times[$i]=$compile_duration

     # Calculate average times
    total_extract_time=0
    total_build_time=0

    for ((j=0; j<=i; j++))
    do
        total_extract_time=$((total_extract_time + extract_times[$j]))
        total_build_time=$((total_build_time + build_times[$j]))
    done

    average_extract_time=$((total_extract_time / (i+1)))
    average_build_time=$((total_build_time / (i+1)))
done

collect_results

echo "Results saved to: $results_file"