After two months of development, Linus Torvalds introduced Linux kernel version 5.3 with which between the changes most notable AMD Navi GPU support is highlighted, Zhaoxi processors and Intel Speed Select Power Management Technology and many more.
The announcement of the new version, Linus reminded all the main promoters of regulation kernel development keep the same behavior for user space components. Changes to the kernel must in no way violate applications that are already running and lead to user-level regressions.
At the same time, a behavior violation can cause not only a change in the ABI, the removal of outdated codes or errors, but also an indirect effect of working properly useful improvements.
What's New in the Linux Kernel 5.3
Of the novelties that stand out in this new version of the Linux Kernel 5.3 we can find that to Amdgpu driver adds initial support for AMD NAVI GPUs (RX5700), which includes Base Controller, Display Interaction Code (DCN2), GFX and Compute Support (GFX10), SDMA 5 (DMA0 System), Power Management, and Media Encoders / Decoders (VCN2).
amdgpu also improved support for Vega12 and Vega20 GPU cards, for which additional memory and power management capabilities were added.
In the DRM driver for Intel video cards for Icelake chips, a new multi-segment gamma correction mode is implemented. Added the ability to display via DisplayPort in YCbCr4: 2: 0 format.
Memory and system services
In kernel 5.3, Introducing support for Intel Speed Select Power Management Technology, what is available on select servers with Intel Xeon processors. This technology allows you to set partition performance and performance settings for different CPU cores, allowing you to prioritize performance for tasks performed on specific cores, sacrificing performance on other cores
On the other hand in the Linux Kernel 5.3 processes in user space have the ability to wait a short time without using loops using the umwait instruction. This instruction, along with the umonitor and tpause instructions, will be offered on the next Intel "Tremont" chips, and will allow implementation of delays that save energy and do not affect the performance of other threads when using Hyper Threading.
For the RISC-V architecture, support for large memory pages has been added (large pages).
Disk subsystem, I / O, and file systems
For XFS file system, multi-threaded inode bypass option is implemented (for example, when checking quotas). New ioctl BULKSTAT and INUMBERS are added, providing access to functions that appeared in the fifth edition of the FS format, such as the inode birth time and the ability to set the BULKSTAT and INUMBERS parameters for each AG group (Assignment Groups) .
While support for directory voids is added for Ext4 file system (unlinked blocks). Flag 'i' was processed for open files (write ban in one situation if flag was set when file was already open).
F2FS adds an option to limit the garbage collector when working in checkpoint = disabled mode.
Added the ability to host a swap file on F2FS with direct I / O. For all users, support has been added for fixing a file and allocating blocks for those files.
Virtualization and security
The core includes a hypervisor for embedded ACRN devices, which is written with real-time task readiness and suitability for use in critical systems in mind. ACRN provides minimal overhead, ensures low latency, and adequate responsiveness when interacting with equipment.
Linux user mode has added a mode to slow down or speed up time in a virtual UML environment to simplify debugging of time-related code. Further, start parameter added which allows to start the system clock from a specific point in epoch format.
Netfilter for nftables adds support for filtering mechanisms hardware-accelerated packages by using the Flow Block API added to the drivers. Complete rule tables with all strings can be carried next to the network adapters. Inclusion is done by binding NFT_TABLE_F_HW to the table.
Simple metadata for Layer 3 and 4 protocols, accept / reject actions, matching by IP and sender / receiver network ports and protocol type are supported.