After two months of intense development, Linus Torvalds finally released Linux 6.18, a peculiar cycle not only because of the magnitude of its improvements, but also because of the tensions and decisions that shaped its development. The removal of Bcachefs, the advancement of Rust in critical components, and a kernel architecture increasingly focused on isolation and security mark a version that arrives more loaded than ever.
In quantitative terms, Linux 6.18 incorporates more than fifteen thousand changes contributed by more than two thousand developers. It's a leap comparable to previous versions, but this time accompanied by an internal overhaul that reorders priorities and suggests, without explicitly stating it, where the ecosystem wants to go.
Main news in Linux 6.18
Within the storage and I/O subsystem, 6.18 introduces one of the most important changes of the cycle: the ldm-pcache's legacy, a persistent memory-based cache layer that leverages PMEM and CXL-DAX devices to accelerate reading and writing while maintaining integrity even after failures.
Another new feature being presented is the eexpulsion of Bcachefs from the main tree. The file system, which had entered the kernel amid discussions, is relegated to an external module via DKMS. Torvalds was categorical: Bcachefs can return, but only if its developer demonstrates a genuine willingness to work by the rules. kernel community collaboration.
In the field of file systems, XFS introduces inline verification improvements, ext4 adopts 32-bit UIDs and GIDs For reserved blocks, F2FS expands its search flexibility, and Btrfs drastically reduces synchronization times. It's a cycle that fine-tunes, optimizes, or hardens virtually every pillar of modern storage.
Moreover, Linux 6.18 does not enable Rust by default, But the language continues to be integrated into strategic areas. The Binder controller, used extensively in Android, now also exists in an implementation written entirely in Rust, supporting Google's strategy to strengthen the structural security of the mobile system.
Also I know Rust debuts a complete set of abstractions for creating USB controllers in RustThis advance, which just two years ago would have sounded improbable, is materializing as one of the most important moves in the long-term evolution of the kernel.
Even GPUs are starting to join this wave: the new Tyr controller, intended for CSF-based Mali chipsIt was created in Rust, although it is still in an experimental state. The same applies to the Nova driver for NVIDIA GPUs with GSP firmware, another symbolic but decisive step towards a future with less C and more guarantees of memory.
Memory and virtualization performance: changes you can feel
The assigner SLUB incorporates a per-CPU cache layer that improves memory allocation and deallocation performance Under real-world workloads, performance increases reached up to 31% according to internal testing. Simultaneously, swap receives an optimization that completely reorganizes its backend, with noticeable performance gains in both compilations and databases. Zswap, meanwhile, eliminates the zpool layer and now works directly on zsmalloc, simplifying the design and reducing overhead.
In virtualization, KVM integrates compatibility with Intel CET, A technology that mitigates attacks based on hop-and-return (ROP) techniques. Also debuting is the ability to handle guests with more than 255 CPUs under Bhyve, support for SEV-SNP in AMD environments, and new secure buffer swapping capabilities via the dibs layer.
Network: security, resilience and a look towards the future
Linux 6.18 incorporates one of the most ambitious advances in network security with the arrival of the PSP protocolPSP, a technology designed by Google to encrypt TCP connections between data centers without the overhead of traditional TLS. PSP relies on UDP and cryptographic offloading to network cards, enabling per-stream encryption and isolating traffic between applications, something unthinkable with older models.
Also Initial support for AccECN is integrated, An evolution of ECN that improves congestion visibility without introducing packet loss. In parallel, the UDP stack receives a major overhaul that increases performance in extreme load scenarios such as DDoS attacks.
Hardware: a more diverse and ambitious kernel
La Hardware compatibility is also expanding. AMDGPU is extending support for new APUs and adding expanded metrics; Intel continues to consolidate its Xe driver for Arc and integrated graphics; Nouveau adopts GSP firmware by default; and Mali and Adreno GPUs receive significant extensions via panthor and msm.
In CPU, the kernel recognizes new ARM Cortex families, while in sound, various drivers for ASoC devices and professional USB cards are incorporated.
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