Steven Barrett's Liquorix Kernel just landed at 7.1-21, shipping two targeted patches that cap and properly drain the PDS scheduler's boost credit to stop unfair task hoarding. The release sits alongside a massive, ongoing Project-C rewrite that's been optimizing cache alignment, SMT awareness, and lock contention since mid-2026. It's an aggressive daily release cycle for a strictly AMD64-only package, but the work keeps the custom scheduler sharp for gaming and low-latency audio workloads. Security also got a facelift with AppArmor as default, Landlock enabled, and two CVEs backported into the mix.

Liquorix Drops 7.1-21 With PDS Scheduler Fixes, Project-C Overhaul Continues

Steven Barrett's Liquorix kernel just hit version 7.1-21, tagged on August 30. Two patches in this release tackle bugs in the PDS scheduler's boost credit decay mechanism, and the larger Project-C optimization effort keeps rolling.

The new version bumps the internal version number to 7.1.12-2. The changelog is straightforward:

* fix bugs with boost credit decay in PDS
 * sched/alt: Cap stored sleep credit at the current nice level
 * sched/alt: Only let earned sleep credit survive a used-up time slice
* update version to 7.1.12-2

If you're running a desktop or gaming rig and notice tasks accumulating sleep credits beyond their priority level, this release should help. The first fix caps stored sleep credit at the current nice level. The second ensures credits get consumed properly when a task runs through its full time quantum.

Project-C Takes Center Stage

The bigger story here is Project-C, the ongoing PDS scheduler rewrite that's been accumulating since mid-2026. Between 7.1-12 and 7.1-21, you're looking at roughly two weeks of aggressive patches.

The commit history shows Barrett wrestling with cache-line alignment, SMT-aware scheduling decisions, and lock contention reduction. Notable changes include per-scheduler counters placed on runqueue lock cache lines, whole-core idle detection, and non-migratable task fast paths. There's also work syncing internal scheduler data structures with upstream Linux 7.1 changes while keeping PDS-specific behavior intact.

It's a lot of work for one person. Barrett operates as a solo maintainer, and the release cadence reflects that intensity—roughly one release per day during active development periods this summer. The packaging repository has crossed 4,000 commits, and the Atom feed reads like a master's thesis in scheduler optimization.

What This Means for Users

Liquorix continues to be a niche offering. It's only built for AMD64. No ARM. No RISC-V. Security-wise, the 7.1 series synced LSM configuration with Debian, Arch, and Ubuntu defaults. AppArmor's set as the default, CONFIG_SECURITY_LOCKDOWN_LSM is enabled, and Landlock made it in. Two CVEs landed too—CVE-2026-43494 for net/rds zerocopy page pin failures, and CVE-2026-31431 for crypto algif_aead out-of-place operation revert.

Users are reporting NVIDIA 580.x driver stability issues, AMD GPU compatibility discussions for RX series cards are ongoing, and there's backporting talk around Valve's dmemcg VRAM booster patch.

It's not for everyone. The aggressive patching schedule means you're testing bleeding-edge scheduler changes daily. But if you're chasing lower frame time deviations or running real-time audio workloads, the PDS scheduler keeps getting sharper.

How to Install Liquorix

This one-liner installer drops the repo and installs the kernel on Debian, Ubuntu, or Arch Linux in one shot:

curl -s 'https://liquorix.net/install-liquorix.sh' | sudo bash