bench-linux

💿 The minimal Linux Live CD ISO for micro-benchmarking 🧪
⚡ Quick Start   📖 Manual   🤝 Contribution   ⚖️ MIT license

What is it?

This is a bunch of scripts allowing anyone to build its own Alpine Linux distribution oriented on clean and reproducible micro-benchmarking under Linux host.

Specifically, this is a Dockerfile that builds you a LiveCD Alpine Linux ISO with special run configuration that isolates CPU 4 (by default, check ./mkimg.benchmark.sh) from the Linux kernel and user-space tasks. Additionally, it stop the usage of "twin" CPU cores that could steal resources between them.

DEMO

CPU 4 is isolated from the scheduler

Why is it needed?

On the regular Linux host	On the bench-linux host

Benchmark variance before and after bench-linux

On the real user-oriented Linux hosts, there are many sources of "noise" that may and will corrupt any benchmarks:

• Background processes
• Hardware interrupts (IRQ)
• Simultaneous multithreading (SMT, "hyper-threading")
• etc.

These noises lead to observing a huge number of "outliers" during long-running benchmarks. Using this, you may significantly reduce their number.

Note

Using this distribution, however, don't save you from all sources of the noise. For example, from CPU throttling caused by overheating.

Quick Start

Check the RELEASES tab on GitHub to ⬇️ download a prebuilt ISO for x86_64 (amd64) with the predefined configuration and follow the Run section.

Important

If your computer has fewer than 5 CPU cores, read the Configuration section first.

Usage

Configuration

Check your systems CPU configuration (for example, using htop):

• You need to determine the number of available CPU cores
• Also, pick the one CPU core which you are going to use for benchmarking
• If you have distinct "performance" and "powersave" CPU cores (for example, in a laptop), you need to run benchmarks on a "performance" core
• Also, your CPU cores most likely support SMT ("hyperthreading"). In this case "twins" will not be able to run something and commonly numbers of disabled "twin"-cores are odd (CPU 1, CPU 3, etc.).

If you have at least 5 CPU cores, the default config is already good for you since it isolates CPU 4. Otherwise, change the parameters in kernel_cmdline at ./mkimg.benchmark.sh.

Build

You need 🐋 Docker. Optionally, GNU make for convenience.

---

Type in your terminal being in the root of this repository:

make

This should automatically build the ISO and place it in the output directory.

---

If you don't have GNU make on your system, you may use the following:

docker build -t bench-linux . # add "--progress=plain" to debug

And after building the image, extract the ISO from it:

mkdir -p output
container=$(docker create bench-linux)
docker cp $container:/iso/. ./output
docker rm $container

Run

You may try out the ISO using any hypervisor like VirtualBox.

Note

Benchmarking in a managed environment is irrelevant.

---

Once you want to run the system on your host, use dd to burn your flash drive or something else:

sudo dd if=output/alpine-benchmark-3.21-x86_64.iso of=DRIVE bs=4K # replace DRIVE with the path

Caution

Be very careful specifying the path to the drive. This command will fully destroy the existing contents of the path destination!

Reboot into the burned drive. It could take about few minutes with hanging screen but after all you will get the Alpine Linux welcome text:

Welcome to Alpine!

The Alpine Wiki contains a large amount of how-to guides and general information
about administrating Alpine systems.
See <https://wiki.alpinelinux.org/>.

You can setup the system with the command: `setup-alpine`

To perform a basic setup, use setup-alpine as suggested:

setup-alpine

On the question about SSH, type "none". It isn't necessary but you most likely will don't use it.

On the last question, type something like /tmp/apkcache. If you leave this question unchanged, you will not be able to install packages in your LiveCD!

---

Use apk to update the package repository and install new packages. For example:

apk update
apk add bash git ssh opam # to benchmark OCaml-based application

Finally, you need to mount your main drive with the application code that you are going to benchmark. For example, it could be a separated /home-partition on your hard drive:

mkdir /mnt/home
mount /dev/nvme0n1p4 /mnt/home # determine the path to your drive before
cd /mnt/home
ls # check that you have your files

Also, it is convenient to use file in order to remember which /dev-file corresponds to your drive:

apk add file
ls /dev # /dev/nvme* represent NVMe SSD drives
file -s /dev/nvme0n1p1 # DOS/MBR boot sector ... FAT (32 bit) ...
file -s /dev/nvme0n1p2 # Linux swap file ...
file -s /dev/nvme0n1p3 # Linux rev 1.0 ext4 filesystem data ... volume name "root" ...
file -s /dev/nvme0n1p4 # Linux rev 1.0 ext4 filesystem data ... volume name "home" ...

Benchmarking

After installing dependencies and building your project, you may also stop all unnecessary background tasks. Determine them using htop.

By default, setup-alpine start some services to allow networking and automatically actualize the system clock:

/etc/init.d/syslog stop
/etc/init.d/networking stop

After stopping non‑essential services, your process tree should look like this:

htop in the tree mode (F5)

Also, ensure the usage of the "performance" power governor for the picked CPU core, if applicable:

cat /sys/devices/system/cpu/cpu4/cpufreq/scaling_governor
# performance

---

Once you've stopped all unnecessary task, run your benchmarks on the picked CPU core (by default, 4). It could be done using taskset or by configuration inside the benchmark itself:

taskset -c 4 sleep 10 # run "sleep 10" on the CPU 4

Additionally, to be sure, you may set NICE -20 for you benchmark or run it in real-time scheduling mode:

renice -20 -p $$ # set NICE -20 for the current shell

ulimit -r unlimited # ensure the ability to use real-time scheduling

chrt -f 99 sleep 10 # run "sleep 10" with SCHED_FIFO (interruptible) scheduling mode and the greatest priority

✨ Good luck and have a nice benchmarking experience!

Contribution

Contributions are always welcome if you have something to improve in this minimal configuration!

While the initial configuration was derived using AI, it was completely rewritten manually and fully AI-produced contributions are undesirable to preserve the simplicity and understandability.

License

This project is licensed under the MIT License - see the LICENSE file for details.