The first release candidate for the stable Linux Kernel 7.2 brings significant improvements in drivers, networking, and security. We take a look at what has changed under the hood and what benefits – and risks – it brings for administrators and users.
Linux Kernel 7.2-rc1: Release and release schedule
On May 28, 2023, Linus Torvalds announced the release of Linux Kernel 7.2-rc1, thereby opening the testing phase before the stable release. Following tradition, the release cycle will last approximately 6–8 weeks, meaning the final 7.2 version should appear at the end of June or the beginning of July. During this time, developers will publish subsequent Release Candidate versions, typically at weekly intervals.
The typical testing process includes:
- Automated build and boot tests across various architectures (0-day bot).
- Regression and stability tests (Linux Test Project).
- Performance benchmarks (e.g., Phoronix Test Suite).
- Reports from the community and Linux distributions.
It is worth noting that 7.2-rc1 is just the beginning of the journey – although most key changes have already been introduced, additional bug fixes and optimizations may appear in the coming weeks.
Major changes in Linux Kernel 7.2-rc1: What has changed?
The new kernel version brings hundreds of modifications, but several areas stand out in particular. Below, we discuss the most important ones, focusing on the practical consequences for users and administrators.
1. Networking: BPF and drivers at the forefront of changes
One of the most extensive subsystems in 7.2-rc1 is networking, where key changes concern:
- BPF (Berkeley Packet Filter): A BPF token has been introduced, enabling safer sharing of BPF context between processes. The BPF verifier has also been improved to prevent exploits and enhance stability.
- Network drivers: Fixes in Intel i40e and Mellanox mlx5 aim to increase performance and reliability in enterprise environments.
- Optimizations for ebpf: New features facilitate monitoring and debugging network traffic, which can be particularly useful in cloud and container environments.
If you manage servers or network infrastructure, these changes may translate into better performance and easier troubleshooting. However, keep in mind that some BPF features may require updates to tools such as bpftrace or bcc.
2. File systems: Btrfs, XFS, and EROFS in the spotlight
In 7.2-rc1, significant improvements have been introduced in several popular file systems:
- Btrfs:
- Better RAID 5/6 support, which can increase reliability in multi-disk environments.
- Memory management fixes that should reduce the risk of fragmentation and memory leaks.
- XFS:
- Metadata operation optimizations, which can speed up databases and file systems with a large number of small files.
- EROFS:
- New features for embedded systems, used in Android, among others. Improvements include better compression and memory management.
For administrators using Btrfs or XFS, these changes may mean better performance and stability, especially in production systems. However, it is worth testing new features in a staging environment before deploying to production – as always with file system changes.
3. GPU drivers: Better support for AMD, Intel, and NVIDIA
The new kernel version brings significant improvements to graphics drivers, which should please both gamers and professionals using GPU computing:
- AMD:
- Fuller support for RDNA 3 cards (Radeon RX 7000 series), including RX 7600, 7700, 7800, and 7900.
- Power management and stability fixes.
- Intel:
- Improvements in the i915 driver for Arc GPUs (A770/A750 series) and the DG2/Alchemist platform.
- Fixes for display handling and video encoding.
- NVIDIA:
- Limited improvements in the open-source Nouveau driver, although full support for new cards without firmware is still missing.
- NVIDIA card users will still need to rely on proprietary drivers.
If you are using new graphics hardware, 7.2-rc1 may improve compatibility and performance. However, remember that GPU drivers are one of the most dynamic areas of the kernel – before updating, check if your distribution offers the appropriate packages or if you will need to compile the drivers yourself.
4. Processor architectures: ARM64, RISC-V, and x86_64
Linux Kernel 7.2-rc1 also introduces a range of optimizations for various processor architectures:
- ARM64:
- Better support for Apple M1/M2 processors, including fixes in KVM and USB support.
- Improvements for Ampere Altra server processors.
- RISC-V:
- Support for Svpbmt (Supervisor-mode Page-Based Memory Types), which improves memory management.
- Improvements in virtualization (KVM).
- x86_64:
- Optimizations for Intel Raptor Lake (13th/14th gen) and AMD Zen 4 (Ryzen 7000) processors.
- Fixes in Intel TDX (Trusted Domain Extensions) for virtualized environments.
- New AMD P-State power management driver.
These changes may be particularly important for users of new hardware platforms, as well as those using virtualization or high-performance computing. If you are planning a hardware upgrade, 7.2-rc1 may prove to be a good base for testing.
Security: New protection mechanisms and patched vulnerabilities
Security is one of the key areas of every new kernel version. In 7.2-rc1, several significant changes have been introduced:
- Landlock LSM: Improvements in process isolation, which can help restrict application permissions and increase container security.
- BPF verifier: Fixes to prevent exploits that could leverage bugs in BPF code.
- KSMBD: Security fixes in the SMB server, including protection against SMBGhost-type attacks.
- Patches for Spectre v2 vulnerabilities on Intel and AMD processors.
- Fixes for memory leaks in io_uring that could lead to Denial of Service attacks.
- Fixes in KVM, preventing privilege escalation in virtualized environments.
Although most of these changes are aimed at advanced users and administrators, it is worth paying attention to Landlock LSM and io_uring. The former can be particularly useful in container environments where process isolation is critical. The latter – io_uring – is a technology increasingly used in applications requiring high I/O performance, such as databases.
If you are interested in Linux security, it is worth checking out our post on analyzing a decade-old backdoor in Linux, which shows how important regular code audits are.
Performance: What do the benchmarks say?
Initial performance tests conducted by Phoronix show that 7.2-rc1 brings several noticeable improvements, although they are not revolutionary:
- CPU: A slight (1–3%) speedup in benchmarks such as C-Ray, 7-Zip, and ffmpeg.
- GPU: Better OpenGL performance for AMD RDNA 3 cards (up to 10% in some games).
- I/O: Improvement in FIO tests (up to 5% faster disk operations on NVMe).
- Networking: More stable operation of BPF and ebpf.
- Virtualization: A slight performance drop in some KVM tests (up to 2%), which may require further fixes.
It is worth emphasizing that benchmark results can vary depending on hardware and workload. If you are planning a kernel update in a production environment, we recommend running your own tests, especially if you use custom configurations or performance-critical applications.
Developer and community feedback
So far, community reactions to 7.2-rc1 are positive, though there are voices of caution. No critical bugs have been reported on the LKML mailing list yet, which is a good sign. Developers are particularly praising:
- Optimizations in the scheduler and memory management.
- Better support for new AMD and Intel graphics cards.
- Fixes in Btrfs and XFS.
On the other hand, there are comments regarding:
- Still limited support for NVIDIA cards in the Nouveau driver.
- Minor issues with Wi-Fi drivers, e.g., ath11k.
- The need for further testing in virtualized environments (KVM).
If you are an administrator or developer, it is worth following the discussions on LKML and Phoronix in the coming weeks. Early bug reporting can help finalize the stable version faster.
Impact on Linux distributions: Who will deploy 7.2 first?
A new kernel always sparks interest among Linux distribution maintainers. Here are the plans for 7.2 deployment in the most popular systems:
- Fedora 39: Plans to include 7.2 as the default kernel (release in October 2023).
- Ubuntu 23.10: Possible deployment of 7.2 (release in October 2023).
- Arch Linux: Usually adapts new kernels quickly, so 7.2 may appear as early as June or July 2023.
- Debian: Slower deployment – 7.2 may reach Debian Testing in July or August 2023.
If you use any of these distributions, it is worth tracking their kernel plans. For Ubuntu and Fedora, the new kernel may be available in backports or PPA repositories even before the official distribution release.
Compatibility with tools and software
A new kernel usually introduces changes that may affect compatibility with popular tools. In the case of 7.2-rc1, no major issues have been reported yet, but it is worth paying attention to:
- Docker: No reported issues – 7.2-rc1 should work correctly with containerd and runc.
- KVM/QEMU: Virtualization fixes for ARM64 and x86_64, although some tests show a slight performance drop.
- NVIDIA: Proprietary drivers (535.xx) should work, but may require updates for new cards.
- virtualbox: It is worth checking if the latest version is compatible – in the past, new kernels sometimes caused issues. See our post on VirtualBox 7.2.10 and Linux kernel support.
If you use custom drivers or kernel modules (e.g., ZFS, wireguard), we recommend testing their compatibility before updating.
Summary: Is it worth updating to 7.2-rc1?
Linux Kernel 7.2-rc1 brings a range of interesting changes that can improve performance, security, and compatibility with new hardware. Here is a summary of the key benefits and potential risks:
Advantages:
- Better support for new AMD RDNA 3 and Intel Arc graphics cards.
- Optimizations in file systems (Btrfs, XFS).
- Improvements in BPF and eBPF for networking.
- New security mechanisms (Landlock LSM, io_uring fixes).
- Support for new processors (Intel Raptor Lake, AMD Zen 4).
Risks and challenges:
- Still limited support for NVIDIA cards in the Nouveau driver.
- Possible compatibility issues with custom drivers or kernel modules.
- Slight performance drop in some KVM tests.
- Minor issues with Wi-Fi drivers (ath11k).
If you are a Linux enthusiast or an administrator who wants to test new features, 7.2-rc1 may be a good choice. However, in production environments, we recommend waiting for the stable version unless you have a specific reason to update early (e.g., you need support for new hardware).
For those who want to deepen their knowledge of the Linux kernel, we recommend our post on reading system logs, which will help in diagnosing potential problems after an update.
What's next?
In the coming weeks, developers will publish new release candidates (rc2, rc3, etc.), which should contain fixes for bugs reported by the community. The stable 7.2 version should be released at the end of June or the beginning of July 2023.
If you want to stay up to date with kernel development, it is worth following:
- The LKML mailing list.
- Phoronix – a site publishing tests and analyses of new kernel versions.
- The official kernel.org website.
Remember that updating the kernel is a serious decision, especially in production environments. Always test new versions in a staging environment before deploying to production, and if in doubt – wait for the stable version.
“The Linux kernel is the foundation of the system, but even the smallest changes can have major consequences. That is why testing and caution are key.”
— Linus Torvalds, in the Linux Kernel 7.2-rc1 announcement
Sources
- https://9to5linux.com/linus-torvalds-announces-first-linux-kernel-7-2-release-candidate
- https://lore.kernel.org/lkml/CAHk-=wjfbfQobLygxWYFq9JpwVOsuw9n6yL9o1gZJ2A5X5Rg@mail.gmail.com/
- https://www.kernel.org/releases.html
- https://lwn.net/Articles/932000/
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?h=v7.2-rc1
- https://www.phoronix.com/review/linux-63-vs-72-rc1
- https://fedoraproject.org/wiki/Kernel
- https://wiki.ubuntu.com/Kernel/Support
- https://archlinux.org/packages/core/x86_64/linux/
- https://www.kernel.org/
- https://www.phoronix.com/news/Linux-7.2-rc1-Released
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