Liquorix kernel 7.2-25 lands with scheduler tweaks, not features
A new maintenance release for the enthusiast kernel leans hard into micro-latency tuning. Barely a blink for most users.
Steven Barrett, who effectively is the Liquorix project, tagged kernel 7.2-25. It rides on top of upstream Linux 7.2.15, the final release of the 7.2 series.
For those keeping score, the actual work is four patches to Liquorix's custom sched/alt code. They check the preempt-mask pick when placing tasks on a core, fix a boundary bug in a cached bitmask, hand "sleep credit" priority boosts to tasks that wake often, and stop tasks that have burned two full slices from banking extra credit.
In other words, this is a tweak to how snappy your system feels. Not a change to what it can do.
What Liquorix actually is
Liquorix isn't a kernel built from scratch. Barrett takes a mainline stable release, layers a curated patchset on top, and slaps a desktop-or-gaming .config over the whole thing. The result is a drop-in replacement for your distro's stock kernel.
It's free under GPL-2.0, builds only for AMD64, and ships packages for Debian, Ubuntu, Arch, and Fedora. The whole pipeline runs through Docker-based CI.
The project's own tagline says it plainly: an enthusiast kernel for "uncompromised responsiveness in interactive systems, enabling low latency compute in A/V production, and reduced frame time deviations in games."
That's a mouthful. The promise underneath is simpler. You install it to make pointer moves, key presses, and game input feel tighter.
The scheduler is the whole game
If there's one thing that defines Liquorix, it's the CPU scheduler. By default it swaps mainline's CFS (now wearing the EEVDF badge) for PDS or BMQ. That single decision is most of the reason the kernel "feels" different.
PDS traces back to Con Kolivas' MuQSS work and leans on a skiplist structure that prioritizes interactive tasks aggressively. BMQ has its own older lineage, harking back to the CK patchset. Barrett picks PDS by default, and Project-C is his ongoing effort to tune it.
Here's the part that matters. Liquorix runs at a 1000 Hz timer tick instead of the 250 Hz most stock kernels use, meaning the kernel re-evaluates scheduling about four times faster. Full preemption. The performance governor instead of schedutil. Shorter timeslices, too.
It's a pile of knobs all aimed at one goal: make your system react to you in roughly a millisecond.
What "Project-C" actually means
Project-C isn't a single patch. It's a running theme across Liquorix releases, named in changelogs going back to the 7.1 and early 7.2 lines, "ongoing Project-C overhaul," "tightened Project-C optimizations."
The work consistently targets micro-latency at the individual-task level. A producer thread and its consumer should land on SMT sibling cores that share L2 cache, since separating them forces cold-cache reloads that spike latency. Everything is measured in microseconds.
The 7.2 line has moved fast. Releases 7.2-3 through 7.2-5 shipped within about 36 hours last September. Then came 7.2-13, 7.2-16, 7.2-17, 7.2-22, and now 7.2-25. That cadence is Barrett iterating, testing, refining, in public. His changelogs read like a lab notebook.
The 7.2-16 release introduced a boot-switchable "PDS sleep credit" you can toggle from the kernel command line. So the accounting logic in 7.2-25 is stacking on something you can actually flip without recompiling. Worth a look if you're into this sort of thing.
Getting it installed
If you're convinced, the drop-in install is painless. On Debian, Ubuntu, Arch Linux, and Fedora you can pipe the installer straight to sudo:
curl -s 'https://liquorix.net/install-liquorix.sh' | sudo bash
Just keep in mind it's AMD64-only, and you'll need to disable Secure Boot. Liquorix does trade raw throughput and battery life for that snappy feel, so it's arguably overkill for anyone whose workload isn't latency-sensitive.
Head here to the Liquorix website.
