Linux Kernel News Archives

The fifth weekly release candidate of Linux 6.9 is now available as the kernel cycle looks to get wrapped up by mid-May.

Ahead of the Linux 6.9-rc5 test kernel being released later today, this week's batch of "x86/urgent" fixes were sent out this morning.

While systemd 255 last year introduced a "blue screen of death" inspired solution with systemd-bsod for presenting logged error messages full-screen, it's not appropriate for all errors. Systemd-bsod can work out for presenting full-screen messages in case of boot failures and other problems where user-space is alive. But the user-space code does little good in case of a kernel panic and similar issues bringing the system to a halt. Set to be introduced now with Linux 6.10 is a parallel "blue screen of death" like error presenting experience with the introduction of the DRM panic handler.

Within yesterday's Linux 6.9-rc4 release is an interesting little nugget by Linus Torvalds to battle Kconfig parsers that can't correctly handle tabs but rather just assume spaces for whitespace for this kernel configuration format.

As expected the Linux 6.9-rc4 test kernel is out today as Linux 6.9 works its way toward release by mid-May.

In addition to a SLUB optimization for extreme scenarios, faster AES-XTS disk/file encryption for modern Intel/AMD CPUs, and other performance optimizations on the way for Linux 6.10, another minor one was queued up this week.

A patch to the Linux kernel's SLUB allocator has been queued ahead of the upcoming Linux 6.10 merge window to help reduce memory consumption in extreme scenarios.

Due to yesterday's Native BHI vulnerability disclosure affecting all Intel processors with this variant of Branch History Injection (BHI) not requiring BPF to exploit, a slew of new Linux kernel stable releases are out today to back-port this security mitigation.

For those making use of AES-XTS crypto for the likes of disk and file encryption on x86_64 CPUs, the upcoming Linux 6.10 kernel cycle is bringing some very tantalizing improvements especially if you are running recent AMD and Intel processors. With AMD Zen 4 processors the benefits can be as much as 155% faster while even Intel Ice Lake and Sapphire Rapids server processors can enjoy 127~151% faster AES-XTS-256.

Linux 6.9-rc3 is released and most notable are the Bcachefs fixes to which Torvalds quipped, "if you had a corrupted bcachefs filesystem you'd probably want this, and if you thought bcachefs was stable already, I have a bridge to sell you. Special deal only for you, real cheap." Plus various other fixes throughout.

Veteran Linux kernel developer Peter Zijlstra is working to wrap-up feature work around the EEVDF kernel scheduler code.

Following the recent upgrade to Rust 1.77, the Linux kernel Rust code is preparing to move to Rust 1.78 that will be released as stable in about one month.

A patch queued in TIP.git's "x86/cpu" branch for collecting ahead of the Linux 6.10 kernel cycle adds support for handling the AMD 0x80000026 leaf to correct CPU topology information reporting for some newer AMD processors.

Adding to the Linux 6.9 features one of the changes that went under my radar is that the s390 kernel builds can now be carried out using the full LLVM compiler stack.

Linus Torvalds just released Linux 6.9-rc2 as the newest test release of Linux 6.9 that will be out as stable in mid-May.

Back in Linux 6.6 the Shadow Stack support was finally merged as part of Intel's Control-flow Enforcement Technology (CET). This years-in-the-making effort allows for better defending against ROP attacks for newer generations of Intel processors. For Linux 6.10, Shadow Stack support is being extended to x32.

Linus Torvalds just released the first release candidate for Linux 6.9 that now marks the formal end of the two-week merge window.

Linux 6.8 dropped the SLAB allocator after its deprecation in v6.5 and now just leaving SLUB for all allocation duties. For Linux 6.9 there is continued cleaning from that SLAB removal as well as making more SLUB improvements.

Workqueues are commonly used within the Linux kernel for asynchronous process execution contexts. With Linux 6.9 the workqueue (WQ) code has seen "significant and invasive" changes.

So far when it comes to Direct Rendering Manager (DRM) / Kernel Mode-Setting (KMS) display drivers for Linux, there are Rust efforts underway for the Apple Silicon kernel graphics driver with the Asahi Linux project as well as the new Nova effort for a modern open-source NVIDIA kernel driver from Red Hat. Also now out from Red Hat is posting the Rust bindings for KMS to review plus porting the existing Virtual KMS driver over to Rust as the "RVKMS" driver.

Loongson continues enabling more kernel functionality for their LoongArch processor port for the upstream Linux kernel. With Linux 6.9 they sent out today a set of patches enabling more features for this Chinese CPU architecture.

With the frame-buffer device "FBDEV" subsystem changes sent out today for the Linux 6.9 kernel, there is support for larger console fonts to better handle today's ~4K displays.

The x86/entry pull request last week for the Linux 6.9 kernel contained just a single patch but it was a significant one at that in that it helps lower the overhead for CR3 writes and the benefits can be visible for workloads like Linux's perf functionality.

The Linux 6.9 kernel has a big rework to the CPU timer code that has been years in the making and has some power and performance benefits.

A slew of new Linux stable kernel point releases were issued today, driven in part for getting out the Intel Register File Data Sampling "RFDS" mitigations for the kernel code as part of this week's disclosure and microcode updates and kernel patches.

The Virtual Function I/O (VFIO) updates for the Linux 6.9 merge window bring a mostly mundane assortment of driver patches and other routine changes. But there is a new driver for NVIDIA's Grace-Hopper superchip.

The EFI updates were merged today for the ongoing Linux 6.9 merge window. This cycle the EFI kernel code is seeing enhancements for confidential computing as well as for satisfy Microsoft's requirements for getting them to sign the x86 shim loader again for UEFI Secure Boot handling.

The Linux work around atomic consoles and threaded printing remains ongoing. This work is particularly interesting as it's the last major blocker before real-time "RT" kernel support can land. This work sadly isn't ready for the new Linux 6.9 cycle but at least some printk clean-ups are landing for issues discovered during the atomic consoles effort.

David Airlie has submitted all of the Direct Rendering Manager (DRM) kernel graphics/display driver updates today for Linux 6.9.

The recently covered overhaul of the x86 CPU topology code to clean-up quite a code mess has been merged for Linux 6.9. Among other benefits, this improved topology code properly accounts for modern Intel Core hybrid systems with a mix of P and HT-less E cores.

A "request for comments" patch series was posted on Monday for a new dynamic kernel stacks feature for Linux. Early testing has shown the potential for significant memory savings.

Linus Torvalds has gone ahead and released Linux 6.8 as stable today rather than drawing this cycle into overtime.

Depending upon how Linus Torvalds is feeling today, Linux 6.8 could debut today as stable and in turn mark the opening of the Linux 6.9 merge window... Otherwise it will be punted off by one week. In any event, there's a lot of interesting work queuing for Linux 6.9 as shared in today's preview.

All of the Rust feature patches have already been submitted in a pull request to Linus Torvalds ahead of the upcoming Linux 6.9 merge window.

Linux 6.8 could debut as stable as soon as tomorrow if all goes well... Linus Torvalds last week was unsure whether an extra release candidate would be needed after the quiet 6.8-rc7 release. This week's seen a continued flow of fixes land, so we'll see what Linus decides on Sunday but in any event there are already a number of early 6.9 pull requests.

Steven Rostedt this week posted some interesting albeit experimental patches for the Linux kernel to support persistent traces that work across a reboot or crash.

Linus Torvalds just issued Linux 6.8-rc7 as we close in on the Linux 6.8 stable release in the next week or two.

The Linux 6.8 kernel continues coming together well and the v6.8-rc6 milestone is now available for testing. If all goes well Linux 6.8 will debut as stable in two weeks but with how things are currently pacing could end up being three weeks.

Sent in overnight was this week's batch of DRM "fixes" for Linux 6.8 that included some mostly minor fixes plus a few notable but small patches to Nouveau, the upstream open-source NVIDIA DRM/KMS kernel driver.

Matthew Wilcox with Oracle who previously worked on the Maple Tree data structure for the Linux kernel along with memory folios has now proposed "Rosebush" as a new hash table data structure for the Linux kernel.

The first "Power11" patches were queued today into the PowerPC's "next" Git branch ahead of the upcoming Linux 6.9 kernel cycle.

Posted on Sunday was the third iteration of the patches working toward the threaded/atomic non-blocking console "NBCON" support that is known to be one of the last blockers to sort out before the remainder of the Linux real-time "RT" patches can be upstreamed.

Linux 6.8-rc5 is out as the latest weekly test release of Linux 6.8 ahead of its stable debut in March.

In development the past several months has been patches to allow changing the compression algorithm used by the hibernation images of the Linux kernel while preserving the system memory contents. With using LZ4 yields faster system restore times from hibernation than the current de facto compression algorithm used of LZO. This work is now queued for introduction in Linux 6.9.

Adding to the list of features slated for the upcoming Linux 6.9 cycle is allowing RISC-V kernel builds to be compiled with Clang Link-Time Optimizations (LTO) enabled.

As more exciting than the Super Bowl (at least for some of us) is the new Linux 6.8-rc4 kernel available for testing.

While the Linux kernel has seen increased activity around dropping old/unused hardware drivers and other support, for old hardware that is still proven to be used on upstream Linux kernel releases does stick around and even will see the occasional fix... The latest example of that is a fix on the way for restoring Linux kernel support for the Transmeta Crusoe, the x86-compatible processor released back in 2000.

Linus Torvalds is up early today and already issued Linux 6.8-rc3 as the newest weekly release candidate of the forthcoming Linux 6.8 kernel.

One of the new features for Linux 6.8 that was merged late was enabling the -Wstringop-overflow compiler option to warn about possible buffer overflows in cases where the compiler can detect such possible overflows at compile-time. While it's nice in theory, issues on GCC has led Linus Torvalds to disabling this compiler option as of now Linux 6.8.

Posted at the start of 2022 was a set of 2.3k patches dubbed "fast kernel headers" to massively speed-up build times for compiling the kernel and to address dependency hell situations. While it was quick to iterate at first and some bits got upstreamed, it's been months since hearing anything new on the fast kernel headers topic. But today a new patch series was posted that's restarting the effort in working towards massively speeding up kernel build times.