Real-time processing is when a program or operating system is fast enough that it can guarantee a reaction to data within a tight, real-world deadline. Typically, real-time computing delivers results from microseconds (one millionth of a second) to milliseconds (one thousandth of a second). Real-time applications that take things down to microsecond latency are stock market’s high-frequency trading (HFT) applications. The much more common millisecond real-time processing is used in banking and telecom applications, digital ad networks, and self-driving cars. People, by the way, have average reaction times of around 250 milliseconds. To deliver it in Ubuntu, Canonical starts with the Ubuntu 22.04 LTS real-time kernel. This is based on the upstream Linux v5.15 kernel. It also integrates the out-of-tree PREEMPT_RT patch for x86_64 and AArch64 architecture. The real-time scheduler can preempt threads in the kernel, including in critical sections, interrupt handlers, and interrupt-disable code sequences, guaranteeing bounded responses. By minimizing the non-preemptible critical sections in kernel code, the PREEMPT_RT patches – not fully upstream yet – make the kernel more preemptive than the mainline Linux kernel. While only in beta, Ubuntu Core 22 real-time kernel enables you to start working on IoT applications, which require ultra-low latency and workload predictability for time-sensitive industrial, telco, automotive, and robotics use cases. Mark Shuttleworth, Canonical’s CEO, said, “With this release, and Ubuntu’s real-time kernel, we are ready to expand the benefits of Ubuntu Core across the entire embedded world.” Beyond the promise of real-time applications, today’s Ubuntu Core provides a robust, fully containerized Ubuntu. It breaks down the monolithic Ubuntu Linux image into packages known as snaps. This includes the kernel, operating system, and applications. Each snap runs in an isolated sandbox that includes the application’s dependencies to make it fully portable and reliable. Canonical’s Snapcraft framework enables on-rails snap development for rapid iteration, automated testing, and reliable deployment. Every device running Ubuntu Core gets its own dedicated IoT App Store. This offers both users and developers full control over what apps they run on their devices and how they run. Ubuntu Core also guarantees transactional mission-critical over-the-air (OTA) updates of all the components, from the kernel to the applications and back again. Updates will either complete successfully or roll back automatically to the previous working version. In short, you can’t brick a device with a faulty or incomplete update. Core Snaps also use delta updates, which cuts down on network traffic. Finally, Ubuntu Core applications use digital signatures to ensure software integrity and provenance. Besides digital signatures, Ubuntu Core also includes other security features. These include secure boot, full disk encryption, secure recovery, and strict sandbox confinement. Brad Kehler, COO of KMC Controls, said, “KMC Controls’ range of IoT devices are purpose-built for mission-critical industrial environments. Security is paramount for our customers. We chose Ubuntu Core for its built-in advanced security features and robust over-the-air update framework. Ubuntu Core comes with 10 years of security update commitment, which allows us to keep devices secure in the field for their long life.” That 10 years of support, combined with the ability to update it over the air, is also important to people who are sick and tired of embedded and IoT devices, which are always being left unsupported by lazy vendors. Now it’s much easier to deliver devices that will be good not just today but for years to come. Ubuntu Core 22 has the potential to be an embedded and IoT device game changer.
