Linux Kernel News Archives

It was another busy week in the Linux 7.1 kernel space that has culminated with the release of Linux 7.1-rc4.

Merged today for the Linux 7.1 kernel is some new documentation surrounding what qualifies as a security bug as well as around responsible use of AI for finding kernel bugs.

Following yesterday's disclosure of the ssh-keysign-pwn vulnerability that allows unprivileged users to read root-owned files, a slew of new stable kernel releases are out today to address this latest Linux security issue.

Following Dirty Frag, Fragnesia, and other Linux kernel vulnerabilities making themselves known in recent days, the latest now is ssh-keysign-pwn.

Following last week's disclosure of the Dirty Frag vulnerability for the Linux kernel, which only finished being patched up in mainline on Monday, Fragnesia is now public as a similar local privilege escalation (LPE) vulnerability.

Prominent Linux kernel engineer Peter Zijlstra of Intel has been working on a set of scheduler patches to help with enhancing the behavior and delivering better results, especially for aging hardware he described as a "potato" -- an Intel Sandy Bridge desktop CPU with AMD Radeon RX 580 Polaris graphics. Benchmark results are promising from this work for gaming on old hardware while other workloads may ultimately stand to benefit too.

Linux 7.0.6 is out as stable this morning to finish mitigating the Dirty Frag vulnerability that was made public last week.

Linus Torvalds just issued the third weekly test candidate of the Linux 7.1 kernel with around a third of the patches being for the networking subsystem.

New tooling being worked on for possible mainline Linux kernel inclusion is Kconfirm as a new tool for detecting misusage and efforts stemming from Kconfig, the configuration system for kernel builds.

Linux 7.1-rc2 is out for testing with its accumulation of initial bug and regression fixes that have been collected over the past week since the Linux 7.1 merge window was capped off.

Merged on Friday ahead of the Linux 7.1-rc2 kernel release due out tomorrow were this week's batch of Direct Rendering Manager (DRM) kernel graphics / display / accelerator driver fixes.

Even while the Linux 7.1 merge window was still ongoing this month, the initial "drm-misc-next" pull request to DRM-Next was sent out for beginning to queue new feature material toward the Linux 7.2 kernel coming this summer.

My initial testing of the Linux 7.1 development kernel on various systems in the lab continues going well. Aside from one main regression in a synthetic micro-benchmark appearing on multiple systems, not seeing much in the way of Linux 7.1 performance concerns thus far and seeing some nice performance gains in select workloads.

Posted to the Linux kernel mailing list this week was the newest revision of a patch series originally started in early 2025 by a NVIDIA engineer for accelerating page migration. Now being worked on by AMD engineers, this accelerated page migration via batch copies and hardware offloading continues to show promising results.

Just days after the Linux 7.1-rc1 kernel release, the Linux kernel's extensible scheduler class "sched_ext" is seeing a lot of bug fixes. Many of these bug fixes aren't just from the Linux 7.1 merge window but a number date back many kernel cycles. This uptick in bug fixes for sched_ext is coming due to increased AI code review.

The Linux 7.1-rc1 kernel was just released for concluding the Linux 7.1 merge window. A lot of new features are in tow for this next kernel version that will then be out as stable in mid-June.

Ahead of the Linux 7.1-rc1 kernel release due out later today for closing the Linux 7.1 merge window, I was curious if all the code removals would lead to a negative change in line count over Linux 7.0. The removals were not enough and Linux 7.1 Git is fast approaching 40 million lines.

In addition to some network drivers on the chopping block due to AI bug reports for obsolete hardware/drivers and Linux 7.1 dropping various drivers for Russia's Baikal CPUs, the Linux 7.1 kernel as of today also dropped some obsolete PCMCIA host controller drivers.

Over the weekend Greg Kroah-Hartman sent out his various pull requests for the areas of the kernel he oversees. Among those is the staging area where this time around the notable activity isn't too much about feature work but many developers making some of their first contributions to the upstream kernel.

Andrew Morton recently sent out his various "MM" related pull requests for the ongoing Linux 7.1 kernel. There are a number of memory management optimizations in this next kernel version, which is always nice to see but all the more so these days with the inflated RAM pricing and other computer component prices.

The Direct Rendering Manager (DRM) kernel graphics driver and accelerator driver changes for Linux 7.1 were recently merged to Git. As usual, it's the Intel and AMD kernel graphics drivers seeing a bulk of the interesting open-source GPU driver activity. Plus ongoing work to make Rust-based GPU drivers more viable.

In addition to the notable libcrypto optimizations and improvements merged during this first week of the Linux 7.1 merge window, the main cryptography subsystem pull was also merged. Notable here are the Intel QuickAssist (QAT) improvements.

The scheduler changes for Linux 7.1 are now in place and may bring performance benefits for at least some systems and workloads.

Merged this week for Linux 7.1 was a rework of the high resolution timer "HRTIMER" subsystem for reducing the overhead of frequently-armed timers, such as the HRTICK scheduler timer. The HRTICK scheduler timer is useful for enhancing system responsiveness and fairness.

Linux libcrypto cryptography subsystem changes for the v7.1 kernel are enabling more optimizations by default and in turn helping to achieve better crypto/hashing performance on this next kernel version.

The extensible scheduler "sched_ext" code for allowing Linux scheduling behavior to be defined via BPF programs is seeing some useful improvements with the in-development Linux 7.1 kernel.

Back during the Linux 7.0 merge window the MMC changes were rejected by Linus Torvalds as "complete garbage" that wasn't building properly and not vetted through linux-next. He went without pulling any MMC changes for the v7.0 cycle while now for Linux 7.1 the code has been better tested and successfully merged.

The Linux 7.1 kernel is bringing performance improvements for Sheaves, the per-CPU caching layer introduced several kernel cycles ago (Linux 6.18) for better efficiency on today's high core count hardware. Sheaves began as an opt-in feature but since Linux 7.0 is now being used for all caches.

The workqueue changes merged today for the Linux 7.1 kernel are significant for today's modern high-end processors where there can be many CPU cores per last level cache (LLC / L3 cache). The new WQ_AFFN_CACHE_SHARD affinity scope can reduce some contention on such systems and help achieve greater performance.

Last month I ran benchmarks showing the very positive performance impact FRED has on Intel's new Panther Lake processors while wondering why Flexible Return and Event Deliver wasn't enabled by default yet on Linux. Hours after that story was published, an Intel engineer posted the patch to enable FRED by default with the rationale they were waiting for hardware to be publicly released in order to evaluate the performance benefit. Days after that the FRED-by-default patch hit tip/tip.git and now as of yesterday that patch is merged for Linux 7.1.

Linux developer Qais Yousef with Google has announced the alpha release of Sched QoS as a new initiative for user-space assisted scheduling. The scheduling model in turn is based in part on Apple's quality of service classes used by iOS for classifying software as user interactive, user initiative, utility, or background tasks.

The clone3() system call in Linux 7.1 is adding three new flags for greater control over the creation of child processes.

The x86/asm changes merged yesterday for the Linux 7.1 kernel with a few low-level improvements.

Code now merged for the Linux 7.1 kernel may provide some negative performance implications for those still running modern Linux kernels on 32-bit hardware. A fundamental change can present cache line alignment and slab sizing implications for 32-bit Linux OS users but will provide for cleaner code with modern 64-bit computing.

While a lot of interesting new features and changes have been merged already for the Linux 7.1 merge window, two pull requests stand out so far for being rejected by Linus Torvalds and complete with his to-the-point commentary.

All of the power management subsystem feature updates have been merged for the Linux 7.1 kernel.

On this first day of the Linux 7.1 merge window, among the early pull requests merged were beginning to land the various VFS pull requests submitted by Christian Brauner. Among that code merged is enabling support for user.* extended attributes on sockets.

In advance of the Linux 7.1 merge window opening, Miguel Ojeda sent out all of the Rust feature updates on Friday. This includes bumping the minimum Rust version for building the Linux kernel as well as a new experimental option that can provide better performance for Rust code within the kernel, alongside other updates.

As expected the stable Linux 7.0 kernel was just released today in marking this next kernel release. The Linux 7.0 milestone comes due to Linus Torvalds' preference of bumping the major version number after hitting X.19 as opposed to any single major change, but in any event there are a lot of great improvements and changes to find with this new kernel version. Linux 7.0 is also what's powering the upcoming Ubuntu 26.04 LTS release.

With Linux 7.0 expected for release later today, in turn the Linux 7.1 merge window will kick off for the two week period of landing all sorts of exciting new features, changes, and removal of old features from the kernel. Here is a look at some of what is on the table for the Linux 7.1 merge window.

The Linux 7.0 kernel is gearing up for its stable release and should be out this coming Sunday, 12 April, barring any major last minute issues.

A big kernel patch series was posted today by longtime Linux developer Thomas Gleixner. The set of 38 patches amount to some big time "spring cleaning" with addressing some code remnants still around that originated back in the very early Linux v0.1 kernel while some other code being cleaned up dates back to the Linux 1.3~2.1 kernel series from the 90's.

Greg Kroah-Hartman, the main Linux stable kernel maintainer and typically viewed as the second-in-command to the Linux kernel development, has turned to new "gregkh_clanker_t1000" fuzzing tooling to help uncover new kernel bugs.

Timed for Easter this year is the seventh weekly release candidate for the Linux 7.0 kernel. If all goes well, Linux 7.0 stable will be out next week.

It's finally time: a patch queued into one of the development branches ahead of the upcoming Linux 7.1 merge window is set to finally begin the process of phasing out and ultimately removing Intel 486 CPU support from the Linux kernel. Anyone still using an i486 CPU with an upstream Linux kernel would be incredibly rare and no known Linux distribution vendors are still shipping with i486 CPU support, but in case you are, you can continue to be running one of the existing Linux LTS kernel versions.

An Amazon/AWS engineer raised the alarms on Friday over the current Linux 7.0 development kernel leading to the throughput for the PostgreSQL database server being around half that of prior kernel versions. The culprit halving the PostgreSQL performance is known but a revert looks like it may not happen and currently suggesting that PostgreSQL may need to be adapted.

Meta's great Linux engineering team have been working through some fresh performance optimizations recently from optimizing /proc/interrupts outputs to renewing their investment in jemalloc. A new Linux kernel patch this week provides another optimization to avoid a possible situation of throttling the TCP throughput unnecessarily on Linux systems.

Rob Clark on Thursday sent out the batch of MSM DRM driver feature changes targeting the upcoming Linux 7.1 merge window. This new work for DRM-Next includes enhancements to the Adreno X2-85 GPU support as found within the new Snapdragon X2 laptop SoCs plus various enhancements to existing Qualcomm graphics/display hardware.

What's more annoying: half-baked AI slop open-source patches or April Fools' Day with programmers trying to have some fun? This year, April 1 is seeming more patches than usual.

After KDBUS failed to make it into the mainline Linux kernel more than one decade ago as an in-kernel version of D-Bus, BUS1 was proposed as a clean sheet design for in-kernel, capability-based inter-process communication (IPC). BUS1 didn't gain enough traction to make it to the mainline kernel and then many of the same developers devised Dbus-Broker as a more performant D-Bus user-space implementation. Well, as a big surprise now, a new version of BUS1 is being worked on for the Linux kernel.