Linus Torvalds suggests the 80486 architecture belongs in a museum, not the Linux kernel
Ancient hardware deserves ancient kernels, but cannot justify consuming developers' valuable time
Linux boss Linus Torvalds has contemplated ending support for the i486 processor architecture in the Linux kernel.
The ancient architecture was up for discussion last week in a thread titled "multi-gen LRU: support page table walks" that considered how the kernel can better handle least-recently-used (LRU) lists – a means of tracking memory pages.
As Torvalds surveyed contributors' code, he appears to have been frustrated by the need to include workarounds that cater to older CPUs. He therefore suggested ending support for old kit could be an easier way to solve memory matters.
"We got rid of i386 support back in 2012. Maybe it's time to get rid of i486 support in 2022?" he wrote.
Deeper into the thread, he returned to the topic with the following observations:
So I *really* don't think i486 class hardware is relevant any more. Yes, I'm sure it exists (Maciej being an example), but from a kernel development standpoint I don't think they are really relevant. At some point, people have them as museum pieces. They might as well run museum kernels.
That position seems to be fueled by a little irritation, as even deeper in the thread Torvalds commented "the kind of work needed to keep i486 alive is the kind of maintenance burden we simply shouldn't have – no developer actually cares (correctly), nobody really tests that situation (also correctly – it's old and irrelevant hardware), but it also means that code just randomly doesn't actually work."
He may well have a point: the i486 architecture debuted in 1989 and was succeeded by Intel's Pentium in 1993.
Intel washed its hands of the '486 in 2007 and today its famously detailed Ark product database contains no mention of the processor family.
Anyone still running the devices has long since resigned themselves to doing so without support, the chance of acquiring new kit, or software developers giving the platform a second thought.
- Don't say Pentium or Celeron anymore, it's just Processor now, says Intel
- Linux Foundation celebrates 30 years of Torvalds' kernel with a dry T-shirt contest
- Linus Torvalds to kernel devs: Grow up and stop pulling all-nighters just before deadline
- Linus Torvalds's faulty memory (RAM, not wetware) slows kernel development
Yet The Register knows of one potentially very influential person who could conceivably weigh in to keep the venerable 80486 alive: Intel CEO Pat Gelsinger, who led development of the tech and has often said within your correspondent's earshot that he was told to make sure it excelled at running AI workloads.
At 100MHz, on a single core, with a 32-bit address space and a whole 16 kilobytes of cache.
Suffice to say the '486 is almost never mentioned when the history of AI is recounted.
And it appears the processor will also soon pass from Linux history to Linux legend. ®