After two months of development Linus Torvalds introduced The kernel release Linux 5.14 . Among the most notable changes: New system calls quotactl_fd () and memfd_secret (), deleting IDE and RAW drivers, new I / O prioritization controller for CGroup, Schedu_Core task scheduling mode, infrastructure for creating verified BPF programs.
The new version received 15883 fixes from 2002 developers,
Patch size – 69 MB (changes affected 12580 files, added 861501 rows of code, removed 321654 lines). About 47% of all presented in 5.14
Changes are associated with device drivers, approximately 14% of the changes have
Attitude to the update code specific to hardware architectures, 13%
associated with a network stack, 3% with file systems and 3% with internal
core subsystems.
- Disk subsystem, enter / output and file systems
- for CGroup Implemented New I / O Prioritization Controller – RQ-QoS, which can control the priority of processing requests for block devices generated by participants of each CGroup. Supports a new priority controller Added to MQ-Deadline I / O Planner.
- in the Ext4 file system implemented The new IOCTL command EXT4_IOC_CHECKPOINT, forcibly discarding all waiting transactions from the log and associated buffers, as well as overwriting the area used by the log in the repository. Change prepared as part of the initiative to prevent information leaks from file systems.
- in btrfs Performance optimization is made: due to the exception of extended journaling extended Attributes In the process of executing FSYNC, the performance of intensive operations with advanced attributes increased to 17%. In addition, when performing the truncation operations that do not affect the extents, the fulfillment of complete synchronization is disabled, which reduced the execution time of the operation by 12%. In SYSFS, a setup has been added to limit I / O bandwidth when checking the FS. Added IOCTL calls to cancel the size and device removal operations.
- in xfs Recycled Implementation of the buffer cache, which is translated on the allocation of memory pages in batch mode. Improved cache efficiency.
- In F2FS, an option for read-only is added and the compressed block caching mode is implemented to improve the performance of random reading. Implemented support for compression of files reflected in memory using the MMAP () operation. For a selective disconnection of compression files on the mask proposed a new option Mounting NoCompress.
- In the ExFat driver, work was carried out to improve compatibility with storage of some digital cameras.