Linux kernel contributor and LWN editor Jonathan Corbet has spoken out about the current state of the codebase supporting the ARM architecture within Linux. “In short, it’s a bit of a mess,” said Corbet on his Linux Foundation Blog.
ARM hardware architecture has a growing prevalence in phones, tablets and a massive range of embedded devices, making it one of the most prolific platforms for Linux. However, describing what he termed the ‘embedded problem’, Corbet highlighted how vendors and developers tend to work in isolation on ARM-specific code enhancements for their own devices.
He claimed that the Linux Foundation had worked successfully to encourage these vendors to contribute their modifications back to the Linux kernel:
“Contributions to the kernel from embedded systems companies have increased greatly; a number of these companies now feature prominently in the list of top-20 contributors.”
However, Corbet went on to explain that problems can still arise because important code that has not been developed in conjunction with the community may not be ready for inclusion in the main kernel. Often, this code is then dumped by the originator who does not have the time to improve it in conjunction with the relevant kernel maintainers.
“There are many diligent and attentive ARM maintainers, but the job has simply gotten too big for them. So the kernel has accumulated a lot of code which duplicates functionality and which does not share consistent, higher-level abstractions,” Corbet wrote.
With the kernel’s ARM-specific code-base now nearly three times the size of the x86-specific code, even Linus Torvalds himself has stepped in, making his dissatisfaction extremely clear and threatening to delay merging updates to the ARM code with the latest release of the main Linux kernel:
“Hint for anybody on the arm list….People need to realize that the endless amounts of new pointless platform code is a problem, and since my only recourse is to say “if you don’t seem to try to make an effort to fix it, I won’t pull from you”, that is what I’ll eventually be doing.”