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Clang Thread Safety Checks Begin Uncovering Bugs In The Linux Kernel

Posted to the Linux kernel mailing list this week were two competing solutions for new LLVM Clang capability / thread safety analysis to the Linux kernel. Two developers had separately been working on implementations for the Linux kernel to make use of Clang's "-Wthread-safety" functionality. Ultimately the upstream kernel will likely settle upon the superior or unified solution while already making use of these new checks is uncovering Linux kernel bugs...

Vulkan Cooperative Matrix Merged For RDNA4 GPUs With RADV, DCC Support Inches Closer

Last week when RADV lead developer Samuel Pitoiset with Valve was commenting on the AMD RDNA4 state with the Mesa RADV driver it was noted that Vulkan cooperative matrix support, Vulkan Video encode/decode, and DCC support were still missing. But in the past week one of the items is now crossed off the list and another is continuing to see new patch activity...

GCC 15 Compiler Showing Off Nice Performance Improvements On AMD Zen 5

With the GCC 15 compiler having progressed to its final stage of development prior to the GCC 15.1 stable release in the likely March~April time frame, I've begun testing the updated GNU Compiler Collection on some test systems. Overall GCC 15 is looking nice and on AMD Zen 5 "znver5" in particular seeing some solid gains over GCC 14. Here are some initial performance benchmarks of the GCC 15 compiler.

Asahi Linux Lead Developer Hector Martin Steps Down As Upstream Apple Silicon Maintainer

Following arguments on the Linux kernel mailing list the past few days over some Linux kernel maintainers being against the notion of Rust code in the mainline Linux kernel and trying to avoid it and very passionate views over the Linux kernel development process, Asahi Linux lead developer Hector Martin has removed himself from being an upstream maintainer of the ARM Apple code...

SMT Remains Very Advantageous For 5th Gen AMD EPYC Performance

After recently re-visiting the AMD EPYC 9005 series AVX-512 performance, I followed up with some fresh SMT benchmarks looking at the performance benefits and power of toggling Simultaneous Multi-Threading on the 5th Gen AMD EPYC "Turin" hardware. Here are some fresh numbers looking at the SMT performance with AMD Zen 5 server processors.

AMD Talks Up IREE/MLIR Programming For Ryzen AI NPUs

While the AMDXDNA driver was merged for the Linux 6.14 kernel for enabling the Ryzen AI NPUs atop a mainline kernel build, there's still the user-space software needed for making use of the neural processing units found in Ryzen AI SoCs. AMD talked more about programming Ryzen AI NPUs last weekend in Belgium at the FOSDEM 2025 developer conference...

Google Interested In The Modern Intel Xe Linux Kernel Driver On Alder Lake

The modern Intel "Xe" Linux kernel Direct Rendering Manager (DRM) driver as the clean successor to the i915 driver has been an experimental option for Tigerlake and newer but only for Xe2 graphics (Lunar Lake / Battlemage) and newer is it used by default. But Google at least for their Chromebook use-cases is entertaining the idea of switching over to the Xe driver rather than the long-used i915 kernel driver for Alder Lake era hardware...

Bisecting The Linux 6.14 Performance Regression With System76 Thelio + AMD Threadripper

Yesterday I showcased Linux 6.14 Git performance worse than Linux 6.13 and 6.12 in a number of multi-threaded workloads. Due to that initial discover being on the lone AMD EPYC Turin 2P server that is always busy running through new benchmarks for future content as well as I am being persistently short on time and constantly under pressure due to the state of the web/ad industry, I didn't expect to get around to digging deeper into the problem in the near-term. But as I ended up being able to reproduce some of the regressions on a System76 Thelio Major workstation at my desk with the still mighty powerful Ryzen Threadripper 7980X, I was able to turn around a quick bisect...

NVIDIA Engineer Talks Up sched_ext Linux Scheduler Possibilities At FOSDEM

Merged last year for the Linux 6.12 kernel was sched_ext for allowing extensible scheduler possibilities by allowing schedulers to be implemented as eBPF code and dynamically loaded into the kernel. This allows for rapidly developing new schedulers as well as exploring other new possibilities around more intelligent kernel scheduling decisions. Meta, Google, Canonical (Ubuntu), and others have been big proponents of sched_ext and NVIDIA is also increasingly vocalizing their support for these extensible scheduler opportunities...

AMD Broadcast TLB Invalidation Patches For Linux Updated, Intel RAR Eyed Next

One of the set of patches for the Linux kernel that we have been looking forward to but that wasn't wrapped up in time for the recent Linux v6.14 merge window was the work enabling use of the AMD INVLPGB instruction on Zen 3 CPUs and newer for broadcast TLB invalidation. This can lead to a nice performance bump in some workloads while the eighth iteration of those patches were posted overnight...
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