Did you know…?

LWN.net is a subscriber-supported publication; we rely on subscribers
to keep the entire operation going. Please help out by buying a subscription and keeping LWN on the
net.

By Jonathan Corbet
January 2, 2025

We are reliably informed by the calendar that yet another year has begun.
That can only mean one thing: the time has come to go out on a limb with a
series of ill-advised predictions that are almost certainly not how
the year will actually go. We have to try; it’s traditional, after all.
Read on for our view of what’s coming and how it may play out.

The extensible scheduling class (sched-ext) will be a game changer.
Already we have seen, in 2024, how the ability to load a CPU scheduler from
user space as a set of BPF programs has unleashed a great deal of
creativity; that was before sched-ext was part of a released kernel. In
2025, this feature will start showing up in more distributions, and more
people will be able to play with it. The result will be a flood of new
scheduling ideas, each of which can be quickly tested (and improved) on
real systems. Some of those ideas will result in specialty schedulers
included with focused distributions (systems for gaming, for example);
others, hopefully, will eventually find their way into the kernel’s EEVDF
scheduler.

Code written in Rust will land in the kernel at an increasing rate
over the course of the year as a result of the increased availability of
abstractions and greater familiarity with the language in the kernel
community. The Rust code that has been merged so far is mostly
infrastructure and proofs of concept; in 2025, we’ll see Rust code that end
users will run — but they may never notice. The number of unstable
language features needed by the kernel will drop significantly as those
features are stabilized by the Rust community.

Another XZ-like backdoor attempt will come to light. Existing code
bases have been scoured for attacks similar to those used against XZ;
little has been found, but that does not mean that there are not other
ongoing efforts, using different techniques, out there. The potential
payoff for a government agency or other su