Linux Kernel 7.0 RC1 Released – A Look at What Changed
Linus Torvalds has released the first release candidate for Linux kernel 7.0.
Key Highlights
This round of changes is largely routine: two‑thirds of the updates touch drivers and subsystems, while the remaining third comprises architecture tweaks, filesystem patches, tooling improvements, and a handful of core fixes. No single feature jump grabs headlines, but the cumulative effect can ripple through your machine in unexpected ways.
One developer noted that after a recent firmware update for a graphics card, the kernel would lock up during boot on certain laptop models. That regression was caught early in this merge window by a vigilant member of the community who had set up a test rig to monitor kernel logs as soon as each commit landed. The fix slipped into the RC1 tree before the final merge deadline, illustrating why even "smooth" release windows can still hide nasty bugs if you’re not watching.
How It Might Affect Your System
If you’re running a recent distribution that pulls from the upstream source or you’ve compiled your own kernel, the new driver updates—especially for PCIe, USB, and NVMe—could improve stability on newer hardware. However, those same patches might introduce subtle regressions in legacy devices that haven’t been exercised by the community’s test matrix. A user who upgraded to 7.0 RC1 after a nightly build of their machine reported intermittent failures when accessing an external SSD via USB‑3.0; the issue turned out to be a timing bug in the new USB controller driver that was later patched in the final release.
For power users, the numerous ACPI and thermal management tweaks may affect how your laptop handles battery usage during heavy workloads. One reviewer found that after enabling the latest power‑supply update, their system’s fan spooled up earlier than before when playing games, a small but noticeable change in thermals.
Things to Watch Out For
The sheer volume of changes means you should keep an eye on log files after installing 7.0 RC1, especially if you rely on custom modules or legacy drivers. A quick dmesg | tail can reveal early warnings that might hint at deeper issues. If your kernel starts complaining about “unknown device” messages from the new pci subsystem, consider rolling back to a previous stable release until the issue is ironed out in a later patch.
The release also brings a host of improvements to the Rust bindings for VFS and various drivers. While these are mainly of interest to developers working on kernel modules in Rust, they signal that the ecosystem is gradually embracing safer languages—something that could reduce memory‑corruption bugs down the line.
How to test the new Linux kernel without breaking your desktop
Downloading the tarball from kernel.org is straightforward, but using git keeps the patch history handy for later troubleshooting.
git clone https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git cd linux git checkout v7.0-rc1
Pulling the exact tag guarantees you’re building the same code Linus tested, which matters because even a single stray commit can re‑introduce a boot‑time regression.
Build with your current config – don’t start from scratch
Most users keep their .config from the running kernel. Running make olddefconfig merges new options into it while preserving everything you already tuned. Skipping this step forces the compiler to enable default values for new drivers, and those defaults sometimes clash with proprietary firmware on older laptops.
Run a quick “make -j$(nproc) && make modules_install”
Compiling in parallel saves time, but watch the build log for warnings about missing symbols. A common symptom after an rc1 merge is “undefined reference to i2c_new_device” caused by a mismatched I²C driver update. Those warnings usually indicate a kernel‑module mismatch that will surface as a device not showing up after reboot.
Do a dry boot in QEMU before touching real hardware
If you have virtualization enabled, spin up the freshly built kernel inside a tiny VM:
qemu-system-x86_64 -kernel arch/x86/boot/bzImage \ -initrd initramfs.cpio.gz -append "root=/dev/sda console=ttyS0" \ -hda /path/to/disk.img -nographic
Booting in QEMU catches the obvious show‑stopper—missing essential drivers or a broken early‑boot path—without risking your workstation. One user reported a complete boot loop after this rc’s new x86/boot changes; the issue was only visible when the kernel tried to load the EFI stub on real hardware, not in the VM.
Verify that critical subsystems survive
After a successful QEMU run, reboot your actual machine with the new kernel once and keep an older kernel entry as fallback. Check these areas:
- Network interfaces come up (run ip link).
- Filesystem mounts succeed (mount | grep /). Pay special attention to overlayfs; a recent update introduced stricter permission checks that broke some Docker setups.
- Power management works (cat /sys/power/state). The new power‑sequencing patches occasionally leave the CPU stuck in C0.
If any of those checks fail, revert to the previous kernel from the GRUB menu and file a bug report with the exact dmesg output. Linus’s merge log shows heavy driver activity—two‑thirds is still drivers—so regressions are expected.
When to stay on rc1 and when to wait for rc2
The “smooth” label only means Linus didn’t have to bisect a boot failure on his test rigs. It doesn’t guarantee that the particular combination of hardware you run won’t hit a snag. If you rely on niche drivers (e.g., a vintage USB‑to‑serial adapter) or custom kernel modules, hold off until rc2 lands and those edge cases are ironed out.
In short
Linux Kernel 7.0 RC1 is a quiet, incremental update rather than a headline‑grabbing overhaul. It refines driver support, tightens power management, and continues the long tradition of polishing the kernel’s core infrastructure. For most users, installing it will be painless, but those who push the boundaries with custom hardware or development builds should monitor for regressions.
That’s all you need to safely give the newest Linux kernel rc1 release a spin without turning your laptop into a paperweight.
