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AMD
AMD CPU improvements like INVLPGB for broadcast TLB invalidation, Zen 5 load latency filtering with perf, AMD P-State driver improvements, initial support for the AMD Versal NET SoC, and more.
Intel
On the Intel side is early work on the kernel-side preparations for Advanced Performance Extensions (APX) and continuing to enhance the Trust Domain Extensions (TDX) support.
CPU
For both Intel and AMD there is also crypto performance improvements like faster CRC code for AVX-512 CPUs and faster AES-CTR with modern x86_64 CPUs.
Graphics
Over on the graphics side there is the very preliminary NOVA driver code merged for the future Rust-written open-source NVIDIA kernel driver. Linux 6.15 also brings Shared Virtual Memory support for the Intel Xe driver, standardized reporting to user-space for hung GPUs, Intel Xe EU stall sampling, AMDGPU support for the OEM i2c interface for RGB lighting and more, and AMD Radeon RX 9070 series fan speed reporting.
Bcachefs
Linux 6.15 also brings many enhancements to the Bcachefs file-system as it works on its "soft frozen" state and working to remove the "experimental" flag from the file-system in the not too distant future.
Other
Some other fun enhancements to Linux 6.15 include IO_uring network zero-copy receive, the new FWCTL subsystem, various Apple driver enhancements, MSEAL protection of system mappings, the new "hugetlb_alloc_threads" option to help boot times on large servers, various kernel scheduler improvements, continued work on Rust programming language abstractions, and landing the Zstd 1.5.7 compression code into the kernel.