We don’t normally cover individual releases of the Linux kernel, partly because most updates are pretty routine. Any given Linux kernel update resolves some bugs, improves support for existing hardware, and makes some forward-looking changes in anticipation of new hardware, and kernel version 5.19 is no exception. Phoronix and OMG! Ubuntu! both have good overviews of the changes.
But there’s one interesting note about this release that Linux kernel creator Linus Torvalds mentions in his release notes: The kernel update is being released using an Arm-powered laptop, specifically the M2-powered version of Apple’s MacBook Air.
“It’s something I’ve been waiting for for a loong [sic] time, and it’s finally reality, thanks to the Asahi team,” Torvalds writes. “We’ve had arm64 hardware around running Linux for a long time, but none of it has really been usable as a development platform until now.”
Torvalds is running Linux on his M2 MacBook with the help of Asahi Linux, a distribution that has been working to reverse-engineer Apple’s hardware. The Asahi team’s goal is to send all of this work upstream into the main Linux kernel so that all distros can benefit, and Asahi has been relatively quick to add support for new Apple chips like the M2 or the M1 Ultra as they’ve been released.
In November 2020, Torvalds wrote that the then-new M1 version of the Air “would be almost perfect” as an Arm Linux laptop but said, “I don’t have the time to tinker with it, or the inclination to fight companies that don’t want to help.”
At a certain level, this news is just mildly interesting trivia—it doesn’t matter to most Linux users what computer Torvalds is currently using, and Asahi Linux is still in a rough, early state where lots of things are half-functional or non-functional. But as Asahi contributor Hector Martin notes, having “real people… using Linux on a real, modern ARM64 platform” with a modern version of the Arm instruction set and a “near-upstream kernel” has knock-on effects that benefit the rest of the ecosystem.
More people using the Arm versions of Linux means more people fixing Arm-related bugs that will benefit all distros, and more people spotting and fixing Arm-specific problems in their own software (“dogfooding,” as Torvalds puts it in his notes). Eventually, the experience of using Linux on Arm hardware should improve for everyone, although these benefits could take years to shake out. But together with hardware efforts like Qualcomm’s upcoming high-performance Arm chips and Microsoft’s commitment to Arm hardware and software, they could make Arm-powered PCs more appealing and competitive alternatives to traditional Intel- and AMD-powered x86 PCs.
Also worth noting is that Torvalds believes that the 5.20 release of the Linux kernel will end up becoming version 6.0, not because of any specific feature updates but because he’s “starting to worry about getting confused by big numbers again.” Kernel versions 3.x and 4.x were also rolled over to the next major version number at or around their 20th release.