Shedding Old Architectures and Compilers in the Kernel
The kernel development process tends to be focused on addition: each new release supports more drivers, more features, and often new processor architectures. As a result, almost every kernel release has been larger than its predecessor. But occasionally even the kernel needs to slim down a bit. Upcoming kernel releases are likely to see the removal of support for a number of unloved architectures and, in an unrelated move, the removal of support for some older compilers.
The Meta architecture was added to the 3.9 kernel as "metag" in 2013; it is a 32-bit architecture developed by Imagination Technologies. Unfortunately, at about the same time as the code was merged, Imagination Technologies bought MIPS Technologies and shifted its attention to the MIPS architecture. Since then, the kernel's support for Meta has languished, and it can only be built with the GCC 4.2.4 release, which is unsupported. On February 21, James Hogan, the developer who originally added the Meta port to the kernel, proposed that it be removed, calling it "essentially dead with no users."
The very next day, Arnd Bergmann, working entirely independently, also proposed removing Meta. Bergmann, however, as is his way, took a rather wider view of things: he proposed that the removal of five architectures should be seriously considered.
Read more at LWN