After two months of development, Linus Torvalds presented the release of the Linux kernel 6.18. Among the most notable changes are dm-pcache for disk caching in non-volatile memory (PMEM), removal of Bcachefs, online XFS checking mode, Binder (Android IPC) and Tyr (GPU Mali) drivers on Rust, ability to create USB drivers in Rust, optimization of caching in the SLUB memory allocator, addressing namespaces by file descriptors, faster paging (swap), verification of BPF programs by digital signature, Intel CET virtualization in KVM, PSP network protocol (a hybrid of TLS and IPsec), support for the AccECN IP extension, and optimization of the UDP stack.
The new version includes 15,035 fixes from 2,217 developers,
patch size – 45 MB (changes affected 13142 files, 601897 lines of code were added, 355006 lines were deleted). In the last issue there was
14334 fixes from 2118 developers, patch size – 46 MB. About 40% of all changes introduced in 6.18 are related to device drivers, approximately 16% of changes are related to updating code specific to hardware architectures, 12% are related to the network stack, 5% are related to file systems, and 3% are related to internal kernel subsystems.
Main innovations in the 6.18 kernel (1, 2, 3):
- Disk subsystem, I/O and file systems
- Added dm-pcache to use persistent memory (CXL memory addressed via DAX device) as an additional high-performance cache in front of slower traditional disk or flash drives. Dm-pcache