The kernel is about to lose its last bit of MMX-specific code, Phoronix reports. Google’s Eric Biggers has a patch in Andrew Morton’s MM tree, likely headed for Linux 7.5 in 2027.
What goes
MMX-optimized XOR in the software RAID code. Per the patch, it’s “used only on 25-year old 32-bit CPUs that lack SSE support — and only on systems that actually have a RAID array.” Pentium MMX and Pentium II boxes will fall back to the “well-tested scalar code.” The MMX memcpy() and friends were removed years ago, so this was the last holdout. The series also cleans up CPU feature checks in the RAID6 code.
My take
Somewhere someone’s running software RAID on a Pentium II, and it’ll keep working, just a little slower. That’s how cruft should go.
God Bless, and Use the Source!