Yesterday Linus Torvalds the leader and creator of the Linux Kernel project released the new version of this, reaching Linux 4.20.
With this new release the new Linux kernel grew by more than 350,000 new lines, spread over about 14,000 changes.
More than 11.400 files have been modified. This brings the new issue in line with the latest releases. Also, the distribution of patches is not unusual, about two-thirds are attributed to drivers, the rest to network, file systems, and tools.
This is not a major release by any stretch of the imagination. Torvalds says: “most of them are networks (controllers, core network fixes, bpf).
There are also some other non-network driver updates and a reverse series of some of the x86 online asm changes that were bypassed by the upcoming compiler support.
In his post he also says:
And as part of "everyone is already taking a break", I can happily report that I already have some early pull requests in my inbox.
I encouraged people to do it one more time, so that people can relax during the end of the year holidays.
In fact, I probably won't start working for a couple of days, but if not, let's try to keep normal hours.
What's New in Linux Kernel 4.20
With this new version of the Kernel, se have added new changes and as mentioned, much more support has been added for devices and especially video cards.
New graphics drivers
A prominent feature in the driver changes for Linux 4.20 is AMD.
Graphics card maker developers added more code for next AMD Vega 20 GPU to be delivered on the new cards, which is almost fully supported.
Additionally, the codenamed GPUs from Raven 2 and Picasso are now supported as well. Nvidia Nouveau's free driver received initial support for HDMI 2.0.
File systems
The file systems in this new kernel are focused on improving the performance of Btrfs. But also Ext4, XFS, F2FS, Device Mapper and Ceph received patches.
During the development of Linux 4.20, developers were also faced with the task of solving an issue that could lead to data loss under certain conditions when using Ext4.
In the end, but it was not the widespread file system failure, the bug was tracked after a long search in the Blk-MQ multi-queue block layer.
It is even more important that the block drivers are prepared to switch to a new version, as the old version was probably already removed in 4.21. As part of this, numerous block controllers have been converted to the Multiqueue API.
Network subsystem
The TCP stack is translated to use the model that determines the earliest exit time of each packet in the distribution of outgoing traffic.
The implemented model tries to solve scaling problems instead of outgoing packet queues, a looping structure based on a timer that determines the earliest time each packet can be sent.
This structure allows you to increase the efficiency of distribution of the packets sent and to calculate the reception and transmission time with greater precision. (RTT, round trip time) during flow formation.
On the other hand, the ability to load, in the form of BPF programs, the handlers that analyze packet headers in a network flow (network flow dissectors) was added, which makes it possible to achieve higher performance and security compared to the previously proposed implementation in C.
How to get Kernel 4.20?
This new version is now available for download and those adventurous who like to compile it on their system can do it immediately.
As for those who prefer to wait for the packages released by their distributions, it is a matter of days in which they are released for their prompt update.