Kbuild speedups, vGPU debate, THP swap

Kernel traffic centered on a kbuild overhaul claiming large build-time wins, contested driver language choices for NVIDIA vGPU, and memory-management work to keep huge pages intact across swap. Linus Torvalds, Andrew Morton, and BPF maintainers delivered pointed reviews across several series.

kbuild series targets major build speedups

A 21-patch v2 proposal to linux-kernel parallelizes kbuild bottlenecks and reports 36 to 90 percent faster kernel builds. Linus Torvalds and other maintainers are actively reviewing the changes. Shorter build cycles matter for anyone iterating on mainline or distribution kernels.

mlx5 VFIO selftest series notes heavy AI authorship

Jason Gunthorpe posted a 10-patch v6 series adding mlx5 support for VFIO self tests on netdev, stating the driver was written largely by Claude AI in about four days then cleaned up with new IFC macros. The work strengthens testing for VFIO device passthrough. Contributors watching AI-assisted kernel patches and mlx5 enablement have a concrete data point.

NVIDIA vGPU VFIO driver draws Rust rewrite push

A 13-patch series introduces an NVIDIA vGPU manager and VFIO variant driver in C. A Rust maintainer proposed a full Rust rewrite over ownership and FFI concerns, and maintainers argued maintainability in a heated thread. The exchange bears on how complex new drivers are accepted and whether Rust becomes preferred for similar hardware support.

Linus NAKs sysctl_field refactoring

An RFC converting SCTP sysctls to a sysctl_field helper was NAK'd by Linus Torvalds for illegible macros and indentation. The author acknowledged the problems and is revising. Shared sysctl helpers affect configuration paths used across many subsystems.

PMD-level swap entries for anonymous THPs

A 29-patch v7 resend adds PMD-level swap entries so anonymous transparent huge pages can survive swap without splitting, with reported fourfold throughput gains. Andrew Morton is engaged on the mm series. Keeping THPs intact across swap improves performance for memory-heavy workloads that page out.

BPF-based RV monitors nacked

An RFC of 20 patches adding BPF pluggable monitors to runtime verification was nacked by Alexei Starovoitov. The author and Steven Rostedt defended domain-specific use cases. The dispute decides whether RV stays specialized or opens to general BPF instrumentation.

BPF LSM xattrs at inode creation

An eight-patch bpf-next series adds a bpf_inode_init_xattr kfunc so BPF LSM programs can set extended attributes atomically inside inode_init_security. Security modules that require xattrs at creation time gain a race-free path. LSM and container security authors are the direct audience.

arm64 128-bit page table entries

Arm posted a 17-patch series adding CONFIG_ARM64_D128 and 128-bit PTE support for FEAT_D128 (VMSAv9-128). The changes extend arm64 memory management for the newer architecture feature. Platforms moving to VMSAv9-128 need this base support in mainline.