The Linux Foundation has launched a Real-Time Linux (RTL) Collaborative Project to accelerate the upstreaming of real-time RT-Preempt patches.
For the last decade, the RTL project, overseen by the Open Source Automation Development Lab (OSADL), has been responsible for maintaining Real-Time Linux patches under the guidance of Thomas Gleixner, with important contributions from Ingo Molnar and others. OSADL has been periodically upstreaming the project’s RT-Preempt (or “Preempt-RT”) patches to mainstream Linux. Now, OSADL is turning over control of the project to the Linux Foundation to bring it closer in line with mainstream Linux kernel development.
Announced today in Dublin at the LinuxCon + CloudOpen + Embedded Linux Conference Europe, the Linux Foundation’s new RTL Collaborative Project “will focus on pushing critical code upstream to be reviewed and eventually merged into the mainline Linux kernel where it will receive ongoing support,” says the not-for-profit Linux advocacy organization. The project will accelerate the mainstreaming of RTL via testing, documentation, a quarterly code plan review, and twice a year face-to-face meetings at the Embedded Linux Conference.
Enabling CONFIG_PREEMPT_RT in the Linux Kernel
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The transfer to the Linux Foundation “will save the industry millions of dollars in research and development,” as well as “improve quality of the code through robust upstream kernel test infrastructure,” says the LF. RTL will focus on advancing hardened, deterministic real-time capabilities for industries including robotics, telecom, manufacturing, aviation, and medical, say the foundation.
Google is the sole Platinum member of the RTL Collaborative Project, while Gold members include National Instruments (NI), OSADL, and Texas Instruments (TI). Silver members include Altera, ARM, Intel, and IBM.
NI makes CompactRIO and CompactDAQ industrial controllers that run its RTL-infused NI Linux Real-Time distribution. Altera, which makes FPGAs, as well as ARM/FPGA SoCs such as the Stratix 10 SX SoC, will soon be acquired by Intel.
Gleixner joins elite LF Fellow club
Thomas Gleixner, who has been the principal maintainer of the RTL project, will follow the project to its new Linux Foundation incarnation as a Linux Foundation Fellow. Existing Fellows include Linux kernel stable maintainer, Greg Kroah-Hartman, embedded Linux developer and Yocto Project maintainer, Richard Purdie, and Linux creator, Linus Torvalds.
Real-time Linux has been steadily improving over the years, although it may never reach the nearly 100 percent deterministic kernels found in many real-time operating systems (RTOSes). RTL applications, which require ironclad reliability, are led by high-end industrial and networking. However, the integration of the RTL project under the Linux Foundation’s umbrella may well be motivated by the foundation’s growing interest in drones and robots with its Dronecode project.
In our recent interview with Lorenz Meier, the core developer and maintainer of the Dronecode-related PX4 project, he said that until RTL efforts receive more active support, most Dronecode related drone vendors will continue to add an RTOS to Linux. “Hard-realtime Linux is still a specialized solution, making RT-Linux somewhat hard to integrate based on standard distributions,” he said.
The new Collaborative Project should accelerate the time it takes to get the latest patches into embedded projects. Already, the RTL kernel “supports the largest range of architectures of any operating system and can leverage Linux device drivers, file systems, and more from the mainline kernel,” says the Linux Foundation.
“The work we’ve been doing on Real-Time Linux has been critical in advancing complex real-time computing systems,” stated Gleixner. “But technology is moving fast, and the RTL project, with support from across the industry, will allow us to sustain this work and successfully integrate with the mainline kernel for long-term support of these technologies.”
The Linux Foundation posted testimonials from all the founding members except Google and IBM. Google’s leading support for the effort may stem in part from its self-driving car and drone projects. All the members, however, are involved in multiple projects and industries where RTL does — or could — play a role. Applications include financial systems, A/V devices, aviation, flight simulators, medical, military, control systems, manufacturing, and “some telecom applications,” according to the Real-Time Linux Collaborative Project site.
“Having this patchset upstream will make Linux a first-class RTOS out of the box,” stated Omid Sojoodi, VP of R&D for Application and Embedded Software at National Instruments.
“We’ve been supporting Real-Time Linux for a long time and look forward to transferring our funding activities to the newly founded Linux Foundation RTL project,” stated Carsten Emde, General Manager, OSADL, which joined the LF back in 2010, and also maintains a related Safety Linux project for industrial applications. “In addition to funding Real-Time Linux, we will continue to help the industry deploy it in products through training, quality assurance, safety processes and legal support.”