The Linux Kernel Has Grown By 225k Lines of Code So Far This Year From 3.3k Developers

After writing yesterday about kernel contributions of AMD vs. NVIDIA vs. Intel, I kicked off the hours-long process of gitstats analyzing the Linux kernel Git repository for some fresh numbers on the current kernel development trends.

Even on an EPYC server with Optane 900p NVMe SSD storage, the gitstats process on the hearty Linux kernel repository is quite a task. But the process is done and offering a fresh look at the current Linux kernel activity in Git. Here are some of the findings:

The kernel repository is at 782,487 commits in total from around 19.009 different authors. The repository is made up of 61,725 files and from there around 25,584,633 lines -- keep in mind there is also documentation, Kconfig build files, various helpers/utilities, etc.

So far this year there has been 49,647 commits that added 2,229,836 lines of code while dropping 2,004,759 lines of code.. Or a net gain of just 225,077 lines. Keep in mind there was the removal of some old CPU architectures and other code removed in kernels this year so while a lot of new functionality was added, thanks to some cleaning, the kernel didn't bloat up as much as one might have otherwise expected. In 2017 there were 80,603 commits with 3,911,061 additions and 1,385,507 deletions. Given just over one quarter to go, on a commit and line count 2018 might come in lower than the two previous years.

Linus Torvalds remains the most frequent committer at just over 3% while the other top contributions to the kernel this year are the usual suspects: David S. Miller, Arnd Bergmann, Colin Ian King, Chris Wilson, and Christoph Hellwig.

So far in 2018 there were commits from 3,320 different email addresses... This is actually significantly lower than in previous years. From 2015 through 2017 there were 4014~4400 different authors (4400 being the authors in 2017). We'll see in the last three months of the year if there is a significant uptick, but this was one of the most surprising findings from these current numbers. In 2013 was the last time there was an author count around ~3300.

When it comes to the top kernel contributors based upon corporate email domain, that list is made up of Intel, Red Hat, the Linux Foundation, Linaro, SUSE, Texas Instruments, and AMD. Keep in mind that the Intel commit count is actually close to 60k commits but that GitStats was reporting intel.com and linux.intel.com emails separately. A bit surprising ARM hasn't inched its way onto that list yet and as shared yesterday NVIDIA isn't close to making it on that list.

The file count in the kernel tree has been mostly flat for the past several years.

While the kernel line count continues steadily rising...

Those wanting to dig through more of these Linux Kernel Git numbers can find the gitstats dump here.