Linux Kernel News Archives

Linus Torvalds released the third weekly release candidate of the forthcoming Linux 6.7 kernel on Sunday night.

A Linux kernel mailing list discussion this holiday weekend that is seeing polarized views on the matter is around a new patch series proposed priority-based shutdown support for drivers/hardware.

Following yesterday's week drm-misc-next pull that added the new Imagination PowerVRM DRM driver, the three patches for atomic DRM_MODE_PAGE_FLIP_ASYNC were queued into drm-misc-next. Now that this atomic async page flip support is in drm-misc-next, next week it should appear in DRM-Next and in turn make it for the Linux 6.8 kernel in the new year.

Released on Thursday were the Linux v6.7-rc2-rt1 real-time "PREEMPT_RT" patches that now re-bases the RT patches against the in-development Linux 6.7 kernel series.

It's been well over a decade since many were wanting open-source Imagination PowerVR graphics when their graphics IP was more common among SoCs, but with the Linux 6.8 kernel in early 2024 there will finally be an upstream, open-source PowerVR DRM kernel graphics driver! But before getting your hopes too high, this is the effort that's only around the newer PowerVR graphics and not the prior generation hardware from many years ago.

Back during the Linux 6.3 kernel support for a number of legacy DRM drivers was removed and now patches have been volleyed for taking things one step further by now eliminating the infrastructure for supporting these older user-space mode-setting graphics/display drivers.

While micro-architecture specific optimizations are rather common place within the Linux x86_64 kernel for various Intel and AMD CPU families with various performance tricks, the ARM64 Linux kernel maintainers are against introducing new micro-architecture specific optimizations as it affects new ARM processors.

Back in Linux 6.2 the in-kernel Zstd compression/decompression code was updated against the Zstd 1.5 upstream state. Now for the Linux 6.8 kernel in the new year the plan is for updating to Zstd 1.5.5 that should provide better compression performance.

Linus Torvalds just released Linux 6.7-rc2 as the second test release of what will become Linux 6.7 stable around the end of the calendar year.

An initial set of drm-misc-next changes has been sent out today to DRM-Next of the very first feature patches to begin queuing until the Linux 6.8 merge window opens up around the start of the new year.

As was expected but now made official: this year's Long-Term Support (LTS) kernel is Linux 6.6.

Since the Linux 6.5 kernel this summer the SLAB allocator has been officially deprecated. This followed the demise of SLOB and trying to get all Linux users over to the SLUB allocator. Patches have now been posted for stripping out the SLAB allocator for good from the mainline kernel.

After a very exciting two weeks, the merge window for Linux 6.7 is now wrapped up and Linus Torvalds has published Linux 6.7-rc1 as the first release candidate leading up to the stable release around the end of the calendar year.

The Linux 6.7 merge window has been downright exciting with additions like Nouveau GSP support and the Bcachefs file-system being added. It's also been downright massive as one of the largest merge windows in recent history in terms of code changes. Here's some statistics of the Linux 6.7 merge window ahead of today's Linux 6.7-rc1 release.

Recently there has been a fair amount of work done to clean-up the Intel/AMD x86 CPU microcode loading (also used by x86_64 CPUs) on Linux that has now been merged for Linux 6.7.

Andrew Morton last week sent out all of the memory management "MM" changes for the Linux 6.7 kernel for which there is a lot of code churn.

With the MIPS CPU architecture at the end of the road in light of RISC-V and LoongArch, there isn't much going on when it comes to MIPS development for the Linux kernel. Most cycles these days just brings bug fixes and removing old/unmaintained platforms. The latest MIPS platform now being removed is AR7 with Linux 6.7.

The staging changes for Linux 6.7 are on the heavier side in part due to many new contributors from Outreachy mailing in their first kernel patches with various minor fixes. But staging is also lightened up a bit by dropping a wired Ethernet and wireless driver as part of the ongoing kernel effort to remove unused and old WiFi drivers.

Ankur Arora of Oracle on Tuesday sent out a set of 86 patches for making the Linux kernel preemptible. This is based on earlier work by prominent Linux kernel engineer Thomas Gleixner.

In addition to the continued FUTEX2 improvements that landed in Linux 6.7, another pull request merged last week for the new kernel bring FUTEX support to IO_uring.

Last week's locking set of changes for the Linux 6.7 kernel add new interfaces for the FUTEX2 system call ABI. This work is making FUTEX2 more extendable and addressing some of the prior limitations.

Linux 6.6 saw EEVDF merged and Intel hybrid cluster scheduling re-introduced. The core scheduler improvements merged this past week for the in-development Linux 6.7 isn't quite as exciting but still there are some healthy scheduler improvements this round.

The crypto subsystem updates for the Linux 6.7 kernel includes the usual churn like various crypto acceleration updates for different SoCs and other routine changes plus is also limiting the role of some insecure and/or obsolete crypto hashing algorithms.

One of the last major blockers before the remaining real-time "PREEMPT_RT" patches can be upstreamed is sorting out threaded / atomic console printing. With the in-development Linux 6.7 kernel, there's been more work upstreamed in that endeavor.

Overnight the mainline Linux kernel has retired support for Intel Itanium (IA-64) processors.

Since Linux 6.6 we've been seeing work upstreamed for sysctl working to remove its sentinel, the final empty element on each sysctl array. This will cut-down on around 64 bytes of bloat per array, help with kernel build times, and an all-around improvement. With Linux 6.7 more of the sysctl changes are ready and hopefully for the v6.8 kernel cycle next year the effort will be completed.

Sent out this morning was the Direct Rendering Manager (DRM) feature pull request of updated graphics/display drivers for the in-development Linux 6.7 kernel. Notable this round is Intel Meteor Lake integrated graphics now being considered stable / enabled out-of-the-box, Intel Lunar Lake graphics support has started to get underway, and AMD continues working on their upcoming hardware platforms.

Linux's FSCRYPT file-system encryption framework allows for native file encryption support on the likes of EXT4, F2FS, and UBIFS. FSCRYPT can make use of inline encryption hardware for accelerating the file-system encryption support and with the Linux 6.7 kernel will work for more scenarios.

As anticipated Linus Torvalds just released the Linux 6.6 kernel as stable.

From the perspective of Linux distributions trying to reduce their attack surface while still making it possible for users to run legacy software without recompiling their kernel, SUSE has spearheaded the effort for boot-time enabling/disabling of x86 32-bit support for whether 32-bit user-space programs and 32-bit system calls can be executed. That code has been submitted for the imminent Linux 6.7 merge window.

One of the many early pull requests sent in for Linux 6.7 were the x86/boot changes that are headlined by a rework to the PE header generation in order to generate a modern, 4K-aligned kernel image view to ultimately aim for better system security.

With Linux 6.6 expected to be released tomorrow as stable, the Linux 6.7 merge window in turn will be opened. Here's a preview of some of the changes expected for this next kernel cycle.

Tomorrow the Linux 6.6 kernel is expected to be released as stable unless Linus Torvalds has last minute reservations and decides to extend the cycle by an extra week. While there were many last minute fixes this week, the changes don't appear to be too scary or invasive. In any event the Linux 6.6 kernel is bringing some exciting features.

The VKMS driver as a virtual kernel mode-setting solution as a software-only implementation of KMS for use with primarily headless Linux systems continues tacking on more features. Maíra Canal and Melissa Wen presented last week at XDC 2023 on the VKMS driver that continues proving very useful for headless platforms as well as for testing purposes.

Linus Torvalds today released the seventh weekly release candidate of Linux 6.6 while is hoping to release the stable kernel version next weekend.

Sent out today were a new batch of drm-misc-next changes intended for Linux 6.7. There's various fixes to the smaller Direct Rendering Manager (DRM) drivers, DRM VM_BIND async documentation, and other small changes. Plus the DRM_GPUVM code has been re-licensed from being GPLv2-only to now GPLv2 or MIT.

Google is proposing a new mseal() memory sealing system call for the Linux kernel. Google intends for this architecture independent system call to be initially used by the Google Chrome web browser on Chrome OS while experiments are underway for use by Glibc in the dynamic linker to seal all non-writable segments at startup.

Linus Torvalds just released Linux 6.6-rc6 and expressed his intention of releasing Linux 6.6 stable in two weeks unless anything wild happens as we approach the end of this kernel cycle.

Queued up this week as part of the HID subsystem fixes ahead of today's Linux 6.6-rc6 kernel test release has been a rather embarrassing bug: unplugging Logitech USB receivers has for the past several months been causing the Linux kernel to crash. After a number of bug reports around this issue from unplugging Logitech keyboard/mice receivers to simply switching away on a USB switch with the device(s) attached, the Linux 6.6-rc6 kernel is carrying the fix and it's also marked for back-porting to existing stable Linux kernel series.

As we approach the Linux 6.6 stable release in a few weeks, Linus Torvalds today released Linux 6.6-rc5 with everything looking "normal" for this week's test release.

A set of patches posted last week can improve the Linux kernel's performance of accounted kernel memory allocations by around 30%.

Currently when hibernating a Linux system LZO compression is used for preserving the memory contents while a new patch series posted today by Qualcomm allow for changing out the compression API used and makes LZ4 a new option during Linux hibernation.

Rust bindings are coming to the Linux kernel's workqueue (WQ) infrastructure that is used for deferring work to a kernel thread for asynchronous process execution.

Linus Torvalds just released Linux 6.6-rc4 as the newest test release for this kernel that is looking to be released as stable around the end of October.

With today's release of kmod 31, Linux's modprobe utility for loading kernel modules can finally allow arbitrary paths to allow loading new kernel modules from anywhere on the file-system.

With roughly just about one month to go until the stable release, Linux 6.6-rc3 was released today as the newest test release of Linux 6.6.

Linus Torvalds released Linux 6.6-rc2 today and it also happens to be 32 years to the day since he introduced the Linux 0.01 kernel version.

Following SLOB's removal and SLAB being deprecated and set for removal, the Linux kernel is all-in on the SLUB allocator. A new patch series posted on Friday is aiming to help prevent the possibility of cross-cache attacks with the SLUB memory allocator in the kernel.

The threaded / atomic console support for the Linux kernel is the last main blocker before the real-time "RT" patches can finally be mainlined.

The Linux kernel currently allows disabling support for 32-bit programs and 32-bit system calls at compile-time, but a new option expected to be introduced with Linux 6.7 this winter will provide a new "ia32_emulation" boot time option to allow unconditionally disabling support for 32-bit programs and system calls.