After two months of development Linus Torvalds introduced the release of the kernel Linux 5.17 . Among the most notable changes: a new performance management system for AMD processors, the possibility of recursive mapping user identifiers for FS, support for portable compiled BPF programs, translation of the pseudo-random number generator on the Blake2S algorithm, the RTLA utility for real-time execution, a new FSCACHE backer Caching Network FS, the ability to attach names to anonymous MMAP operations.
The new version received 14203 fixes from 1995 developers,
Patch size – 37 MB (changes affected 11366 files, added 506043 lines of code, 250954 lines were removed). About 44% of all of all changes presented in 5.17 are associated with devices drivers, about 16% of the changes are related to the update of the code specific for hardware architectures, 15% is associated with a network stack, 4% with file systems and 4% with internal core subsystems.
basic innovations In the kernel 5.17:
- disk subsystem, enter / output and file systems
- implemented The ability to nested mapping identifiers of users of the following file systems used to match the files of a certain user on an affected alien section with another user in the current system. The added ability allows you to recursively use mapping over the file systems for which Mapping is already applied.
- completely rewritten FSCACHE subsystem used to organize caching on a local file system transmitted via network file systems. The new implementation is characterized by a significant simplification of the code and the replacement of complicated planning and monitoring of objects of objects to simpler mechanisms. Support for the new FSCache is implemented in the CIFS file system.
- In the event tracking subsystem in FS FANOTIFY, a new type of FAN_RENAME events has been implemented, which allows you to intercept the operation of renaming files or directories (previously for rename processing two separate events FAN_MOVED_FROM and FAN_MOVED_TO).
- in the file system BTRFS