Linux 4.9 Roars as Largest Linux Release Ever
On December 11, Linus Torvalds officially announced the release of the Linux 4.9 kernel, codenamed 'Roaring Lionus', marking the debut of the sixth and final Linux kernel release of 2016.The new release follow the Linux 4.8 milestone that debuted on October 2
According to Torvalds, the Linux 4.9 kernel release is noteworthy for a number of reasons.
"I'm pretty sure this is the biggest release we've ever had, at least in number of commits," Torvalds wrote in in his announcement message for the new kernel. "If you look at the number of lines changed, we've had bigger releases in the past, but they have tended to be due to specific issues (v4.2 got a lot of lines from the AMD GPU register definition files, for example, and we've had big re-organizations that caused a lot of lines in the past: v3.2 was big due to staging, v3.7 had the automated uapi header file disintegration, etc)."
"In contrast,4.9 is just big," Torvalds wrote.
As always, the bulk of most new Linux kernels is driver updates, with Torvalds specifically calling out GPU and networking driver updates in particular.
From an architecture standpoint, Linux 4.9 is noteworthy as it vastly more ARM support than any prior Linux release.
"Here are 749 patches for ARM SoCs for this merge window, a bit less than average this time," Linux kernel developer Arnd Bergmann wrote in his ARM pull request for Linux 4.9. "We support 29 new machines but all five SoCs we add are in a family that is already supported."
Those 749 patches were contributed by 165 different developers. Among the new ARM boards supported by Linux 4.9 is the Raspberry Pi Zero.
Linux 4.9 is also noteworthy in that it marks the completion of Protection Keys support which adds new security protection for memory.
"This is the final step of Protection Keys support which adds the syscalls so user space can actually allocate keys and protect memory areas with them," Linux kernel developer Thomas Gleixner wrote in his Git Pull request.
Sean Michael Kerner is a senior editor at LinuxPlanet and InternetNews.com. Follow him on Twitter @TechJournalist