Linux Kernel integrates a large number of exciting improvements in 2021 and increases support for new hardware. Although this year is exciting, if you look at the number of submissions and rows, it is lower than before. The technology media Phoronix analyzed some improvements and changes of Linux Kernel in 2021, as well as annual Git development statistics.
As of yesterday, when GitStats was run on the Linux kernel source tree, the repository had 1,060,172 commits from approximately 243,000 different authors. The source code tree currently consists of 32.2 million lines, involving 74,300 files. With the continuous emergence of new features and the expansion of hardware support, the number of lines in the Linux kernel continues to rise at a fairly steady rate.
Although many heavy features and hardware support were added in 2021, Kernel only had 73,700 submissions in 2021. In contrast, there were 90,200 submissions in 2020, 82,800 submissions in 2019, and 80,100 submissions in 2018. The last submission of fewer than 73,000 submissions dates back to 2013 when the number of submissions was 70,900.
Although part of the reason is that there were only 5 major kernel releases in 2021, and 6 major releases in some years, in turn, the additional merger window in that calendar year resulted in a large flow of new submissions… At the same time, Linux 5.16 will be released in a few weeks, which will launch the merge window for Linux 5.17 in January.
In addition to much fewer submissions than usual, in 2021, Linux Kernel added 3.2 million rows and deleted 1.3 million rows, which is down from 4 million rows and 1.5 million rows in 2020. As usual, Linus Torvalds is the most prolific committer on the source tree. Next, the top five committers of the Linux kernel source tree are David S. Miller, Arnd Bergmann, Christoph Hellwig, Lee Jones, and Jakub Kicinski and other long-term well-known kernel contributors.
In 2021, there are 4421 different emails related to Linux kernel submissions, which is a decrease from 4,603 in 2020, but an increase from 4,383 in 2019.