OS PLATFORMS

More than 140,000 lines of code bite the dust as ancient CPUs, bus mice, and other legacy leftovers face the chop

Linux kernel 7.1 is out, bringing significant changes that have been brewing for years – including the long-promised removal of support for Intel's 486 chip and its contemporaries. More than 140,000 lines of code have been chopped, with more facing deletion.

Back in May 2025, we wrote that kernel 6.15 would drop 486 support, but that change was canceled at the last minute. Now it's in: in April, Penguin Emperor Linus Torvalds merged the big change that we described back then. More work is still ahead before this is completely gone, though. The Reg reported on the Russian Baikal family of CPUs way back in 2014, and again in 2021, but now Linux support for Baikal hardware has been removed, as has support for ancient bus mouse ports.

We've also previously described 7.1's new NTFS driver, NTFSplus. It's optional for now, but South Korean filesystems boffin Namjae Jeon has revived and rewritten the original read-only NTFS driver from the 1990s. Most importantly, now it's able to write to NTFS volumes as well as read from them, and it's been modernized in line with current kernel filesystem methods. Linux Weekly News (LWN) explained the change in its January Filesystem Medley.

Along with the new driver, there's also a new and improved version of the additional ntfsprogs utilities, called ntfsprogs-plus. This gives Linux the ability to repair some forms of NTFS corruption and errors – so we suspect that the various Linux-based live rescue media such as SystemRescue, GParted Live, and Grml may be quick to adopt kernel 7.1. This reminds us of what might have been the first time we reported on some of Namjae's filesystem finesse, when his code to repair exFAT volumes was added back in 2022.

NTFSplus stands to completely replace the driver that Paragon Software donated back in 2020, as we described in April. It also seems likely that the old read-only NTFS driver will be removed too, as NTFSplus is based on that code. As it happens, exFAT support has been improved too. Contiguous space for files can be pre-allocated without zeroing the blocks first, making the process faster, and reducing fragmentation so storage media stays faster for longer. There are also improvements in ext4 and Btrfs handling. The swap memory subsystem has been overhauled, and should be faster. With RAM prices still high and thus renewed interest in memory and cache compression tools, we suspect that there's much more to do here.

There are, of course, many smaller changes, some of which we've previously covered – including the removal of a whole collection of ancient communications devices. In 2022, our own Steven J. Vaughan-Nichols introduced the new io_uring API. In doing so, he also mentioned the new eBPF functionality, which we had days previously attempted to summarize. In 7.1, those two meet: now eBPF code can handle io_uring scheduling.

The extensible kernel scheduler, which we've previously mentioned as an advanced feature of Oracle Linux's UEK-next kernel, has now been merged.

Kernel 7.1 has improved power management for both AMD and Intel chips, as well as battery-status reporting on Apple M1 and M2-based laptops. The security of KVM virtualization on Arm has been tightened up, and so has that around accessing PIDs (process IDs) in the /proc virtual filesystem. The CIFS network filesystem – or SMB, as most of us call it – now has explicit support for creating temporary files.

Intel FRED support debuted way back in kernel 6.9 but it's now on by default, and it helps performance on AMD processors as well. Kernel Rust support now needs Rust 1.85.

For a deep dive into all the changes, as ever, LWN is the place to go. All this and much, much more is described in the articles on the first half of the 7.1 merge window and the rest of the 7.1 merge window. ®