The Linux kernel continues its rapid development pace with the official release of version 6.15 on May 25, 2025. Announced by Linus Torvalds, this latest stable release brings significant improvements across performance, hardware support, and emerging technologies.
Key Technical Improvements
Linux 6.15 introduces several groundbreaking technical enhancements that push the boundaries of what the kernel can do:
Rust Integration Expands
Building on previous efforts to modernize the kernel codebase, 6.15 extends Rust support to critical subsystems including hrtimer (high-resolution timers) and ARMv7 architecture. This move represents a major step toward memory-safe kernel development without sacrificing performance.
CPU and Scheduling Enhancements
- New setcpuid= boot parameter for x86 CPUs, giving administrators finer control over CPU feature detection
- Enhanced sched_ext capabilities that count and report internal scheduler events, improving system monitoring and debugging
- Nested virtualization support for VGICv3 on ARM processors, enabling more efficient cloud and container deployments
Filesystem and Storage Updates
The kernel now includes a new API to receive real-time information about mount and unmount events, streamlining filesystem management for system administrators. Storage security also gets a boost with hardware-wrapped encryption keys in the block layer, while EROFS gains 48-bit block addressing support for handling larger filesystems.
RISC-V Architecture Advances
RISC-V continues to gain traction in the Linux ecosystem. Kernel 6.15 adds support for several important extensions:
- BFloat16 floating-point extension – Improves machine learning and scientific computing performance
- Zaamo and Zalrsc extensions – Atomic memory operations for better concurrency
- ZBKB extension – Cryptography acceleration for RISC-V processors
These additions position RISC-V as an increasingly viable alternative to x86 and ARM in both embedded systems and data center environments.
Expanded Hardware Support
New drivers in kernel 6.15 bring official Linux support to a wide range of consumer and development hardware:
- Apple Touch Bar – Full functionality for MacBook Pro users running Linux
- Google Pixel Pro 6 smartphone support
- MYIR Remi Pi development board
- Huawei Matebook E Go embedded controller
- Milk-V Jupiter RISC-V single-board computer
- HP laptops with CS35L41 HDA audio chips – Fixing long-standing audio issues
What’s Next: Linux 6.17
Development never stops in the Linux world. The next major release, kernel 6.17, is currently in its fifth release candidate (6.17-rc5) with the stable version expected in late September 2025. Early previews suggest continued improvements in power management, graphics drivers, and network stack optimization.
A Growing Codebase
As of January 2025, the Linux kernel source code surpassed 40 million lines—a testament to its continuous evolution and the contributions of thousands of developers worldwide. Despite this massive scale, the kernel maintains its reputation for stability and performance across devices from embedded systems to supercomputers.
How to Upgrade
For users wanting to test kernel 6.15:
# Check your current kernel version
uname -r
# Ubuntu/Debian users (using mainline PPA)
sudo add-apt-repository ppa:cappelikan/ppa
sudo apt update
sudo apt install mainline
# Use mainline GUI to install kernel 6.15
# Fedora users
sudo dnf update kernel
# Arch Linux users
sudo pacman -Syu linux
Note: Always backup your system before upgrading to a new kernel. While 6.15 is stable, hardware compatibility varies by system.
Conclusion
Linux kernel 6.15 represents another solid step forward for the open-source operating system. With improved Rust integration, expanded RISC-V support, and dozens of new hardware drivers, it demonstrates Linux’s ability to adapt to emerging technologies while maintaining backward compatibility.
Whether you’re running Linux on a decade-old laptop or the latest RISC-V development board, kernel 6.15 has something to offer.