RMT.rs: High-Performance Registration Path for RMT using Rust by gbasso

Description

The SUSE Repository Mirroring Tool (RMT) is a critical component for managing software updates and subscriptions, especially for our Public Cloud Team (PCT). In a cloud environment, hundreds or even thousands of new SUSE instances (VPS/EC2) can be provisioned simultaneously. Each new instance attempts to register against an RMT server, creating a "thundering herd" scenario.

We have observed that the current RMT server, written in Ruby, faces performance issues under this high-concurrency registration load. This can lead to request overhead, slow registration times, and outright registration failures, delaying the readiness of new cloud instances.

This Hackweek project aims to explore a solution by re-implementing the performance-critical registration path in Rust. The goal is to leverage Rust's high performance, memory safety, and first-class concurrency handling to create an alternative registration endpoint that is fast, reliable, and can gracefully manage massive, simultaneous request spikes.

The new Rust module will be integrated into the existing RMT Ruby application, allowing us to directly compare the performance of both implementations.

Goals

The primary objective is to build and benchmark a high-performance Rust-based alternative for the RMT server registration endpoint.

Key goals for the week:

1. Analyze & Identify: Dive into the SUSE/rmt Ruby codebase to identify and map out the exact critical path for server registration (e.g., controllers, services, database interactions).
2. Develop in Rust: Implement a functionally equivalent version of this registration logic in Rust.
3. Integrate: Explore and implement a method for Ruby/Rust integration to "hot-wire" the new Rust module into the RMT application. This may involve using FFI, or libraries like rb-sys or magnus.
4. Benchmark: Create a benchmarking script (e.g., using k6, ab, or a custom tool) that simulates the high-concurrency registration load from thousands of clients.
5. Compare & Present: Conduct a comparative performance analysis (requests per second, latency, success/error rates, CPU/memory usage) between the original Ruby path and the new Rust path. The deliverable will be this data and a summary of the findings.

Resources

• RMT Source Code (Ruby):
  • https://github.com/SUSE/rmt
• RMT Documentation:
  • https://documentation.suse.com/sles/15-SP7/html/SLES-all/book-rmt.html
• Tooling & Stacks:
  • RMT/Ruby development environment (for running the base RMT)
  • Rust development environment (rustup, cargo)
• Potential Integration Libraries:
  • rb-sys: https://github.com/oxidize-rb/rb-sys
  • Magnus: https://github.com/matsadler/magnus
• Benchmarking Tools:
  • k6 (https://k6.io/)
  • ab (ApacheBench)

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Learn a bit of embedded programming with Rust in a micro:bit v2 by aplanas

Description

micro:bit is a small single board computer with a ARM Cortex-M4 with the FPU extension, with a very constrain amount of memory and a bunch of sensors and leds.

The board is very well documented, with schematics and code for all the features available, so is an excellent platform for learning embedded programming.

Rust is a system programming language that can generate ARM code, and has crates (libraries) to access the micro:bit hardware. There is plenty documentation about how to make small programs that will run in the micro:bit.

Goals

Start learning about embedded programming in Rust, and maybe make some code to the small KS4036F Robot car from keyestudio.

Resources

• micro:bit
• KS4036F
• microbit technical documentation
• schematic
• impl Rust for micro:bit
• Rust Embedded MB2 Discovery Book
• nRF-HAL
• nRF Microbit-v2 BSP (blocking)
• knurling-rs
• C++ microbit codal
• microbit-bsp for Embassy
• Embassy

Diary

Day 1

• Start reading https://mb2.implrust.com/abstraction-layers.html
• Prepare the dev environment (cross compiler, probe-rs)
• Flash first code in the board (blinky led)
• Checking differences between BSP and HAL
• Compile and install a more complex example, with stack protection
• Reading about the simplicity of xtask, as alias for workspace execution
• Reading the CPP code of the official micro:bit libraries. They have a font!

Day 2

• There are multiple BSP for the microbit. One is using async code for non-blocking operations
• Download and study a bit the API for microbit-v2, the nRF official crate
• Take a look of the KS4036F programming, seems that the communication is multiplexed via I2C
• The motor speed can be selected via PWM (pulse with modulation): power it longer (high frequency), and it will increase the speed
• Scrolling some text
• Debug by printing! defmt is a crate that can be used with probe-rs to emit logs
• Start reading input from the board: buttons
• The logo can be touched and detected as a floating point value

Day 3

• A bit confused how to read the float value from a pin

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Learn how to use the Relm4 Rust GUI crate by xiaoguang_wang

Relm4 is based on gtk4-rs and compatible with libadwaita. The gtk4-rs crate provides all the tools necessary to develop applications. Building on this foundation, Relm4 makes developing more idiomatic, simpler, and faster.

https://github.com/Relm4/Relm4

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Arcticwolf - A rust based user space NFS server by vcheng

Description

Rust has similar performance to C. Also, have a better async IO module and high integration with io_uring. This project aims to develop a user-space NFS server based on Rust.

Goals

• Get an understanding of how cargo works
• Get an understanding of how XDR was generated with xdrgen
• Create the RUST-based NFS server that supports basic operations like mount/readdir/read/write

Result (2025 Hackweek)

• In progress PR: https://github.com/Vicente-Cheng/arcticwolf/pull/1

Resources

https://github.com/Vicente-Cheng/arcticwolf

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Mail client with mailing list workflow support in Rust by acervesato

Description

To create a mail user interface using Rust programming language, supporting mailing list patches workflow. I know, aerc is already there, but I would like to create something simpler, without integrated protocols. Just a plain user interface that is using some crates to read and create emails which are fetched and sent via external tools.

I already know Rust, but not the async support, which is needed in this case in order to handle events inside the mail folder and to send notifications.

Goals

• simple user interface in the style of aerc, with some vim keybindings for motions and search
• automatic run of external tools (like mbsync) for checking emails
• automatic run commands for notifications
• apply patch set from ML
• tree-sitter support with styles

Resources

• ratatui: user interface (https://ratatui.rs/)
• notify: folder watcher (https://docs.rs/notify/latest/notify/)
• mail-parser: parser for emails (https://crates.io/crates/mail-parser)
• mail-builder: create emails in proper format (https://docs.rs/mail-builder/latest/mail_builder/)
• gitpatch: ML support (https://crates.io/crates/gitpatch)
• tree-sitter-rust: support for mail format (https://crates.io/crates/tree-sitter)

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Backporting patches using LLM by jankara

Description

Backporting Linux kernel fixes (either for CVE issues or as part of general git-fixes workflow) is boring and mostly mechanical work (dealing with changes in context, renamed variables, new helper functions etc.). The idea of this project is to explore usage of LLM for backporting Linux kernel commits to SUSE kernels using LLM.

Goals

• Create safe environment allowing LLM to run and backport patches without exposing the whole filesystem to it (for privacy and security reasons).
• Write prompt that will guide LLM through the backporting process. Fine tune it based on experimental results.
• Explore success rate of LLMs when backporting various patches.

Resources

• Docker
• Gemini CLI

Repository

Current version of the container with some instructions for use are at: https://gitlab.suse.de/jankara/gemini-cli-backporter

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bpftrace contribution by mkoutny

Description

bpftrace is a great tool, no need to sing odes to it here. It can access any kernel data and process them in real time. It provides helpers for some common Linux kernel structures but not all.

Goals

• set up bpftrace toolchain
• learn about bpftrace implementation and internals
• implement support for percpu_counters
• look into some of the first issues
• send a refined PR (on Thu)

Resources

• https://bpftrace.org/
• https://docs.kernel.org/

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Add Qualcomm Snapdragon 765G (SM7250) basic device tree to mainline linux kernel by pvorel

Qualcomm Snapdragon 765G (SM7250) (smartphone SoC) has no support in the linux kernel, nor in u-boot. Try to add basic device tree support. The hardest part will be to create boot.img which will be accepted by phone.

UART is available for smartphone :).

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dynticks-testing: analyse perf / trace-cmd output and aggregate data by m.crivellari

Description

dynticks-testing is a project started years ago by Frederic Weisbecker. One of the feature is to check the actual configuration (isolcpus, irqaffinity etc etc) and give feedback on it.

An important goal of this tool is to parse the output of trace-cmd / perf and provide more readable data, showing the duration of every events grouped by PID (showing also the CPU number, if the tasks has been migrated etc).

An example of data captured on my laptop (incomplete!!):

          -0     [005] dN.2. 20310.270699: sched_wakeup:         WaylandProxy:46380 [120] CPU:005
          -0     [005] d..2. 20310.270702: sched_switch:         swapper/5:0 [120] R ==> WaylandProxy:46380 [120]
...
    WaylandProxy-46380 [004] d..2. 20310.295397: sched_switch:         WaylandProxy:46380 [120] S ==> swapper/4:0 [120]
          -0     [006] d..2. 20310.295397: sched_switch:         swapper/6:0 [120] R ==> firefox:46373 [120]
         firefox-46373 [006] d..2. 20310.295408: sched_switch:         firefox:46373 [120] S ==> swapper/6:0 [120]
          -0     [004] dN.2. 20310.295466: sched_wakeup:         WaylandProxy:46380 [120] CPU:004

Output of noise_parse.py:

Task: WaylandProxy Pid: 46380 cpus: {4, 5} (Migrated!!!)
        Wakeup Latency                                Nr:        24     Duration:          89
        Sched switch: kworker/12:2                    Nr:         1     Duration:           6

My first contribution is around Nov. 2024!

Goals

• add more features (eg cpuset)
• test / bugfix

Resources

• Frederic's public repository: https://git.kernel.org/pub/scm/linux/kernel/git/frederic/dynticks-testing.git/
• https://docs.kernel.org/timers/no_hz.html#testing

Progresses

isolcpus and cpusets implemented and merged in master: dynticks-testing.git commit

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pudc - A PID 1 process that barks to the internet by mssola

Description

As a fun exercise in order to dig deeper into the Linux kernel, its interfaces, the RISC-V architecture, and all the dragons in between; I'm building a blog site cooked like this:

• The backend is written in a mixture of C and RISC-V assembly.
• The backend is actually PID1 (for real, not within a container).
• We poll and parse incoming HTTP requests ourselves.
• The frontend is a mere HTML page with htmx.

The project is meant to be Linux-specific, so I'm going to use io_uring, pidfs, namespaces, and Linux-specific features in order to drive all of this.

I'm open for suggestions and so on, but this is meant to be a solo project, as this is more of a learning exercise for me than anything else.

Goals

• Have a better understanding of different Linux features from user space down to the kernel internals.
• Most importantly: have fun.

Resources

• https://github.com/mssola/pudc

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