Linux 7.2 Lands With 2,100 Contributors, Faster Ext4 and Cache-Aware Scheduling

Q: Why did a highly anticipated Linux scheduler update cause severe gaming freezes right before release?

It froze games because Linux 7.2’s new default DRM GPU scheduler policy, called FAIR, regressed badly under sustained full-load gaming on some AMD Radeon systems, especially the RX 9070 XT. The issue was not the main CPU scheduler work such as Cache Aware Scheduling. It was a graphics-side scheduler change in the DRM subsystem that replaced the older FIFO policy with FAIR. In late testing, users reported that when the GPU stayed near 100% utilization in games, frame rates could collapse to around 10 fps or the foreground game could freeze entirely while audio kept playing. In some cases, KDE Plasma Wayland sessions also locked up. The bug appeared reproducible under heavy GPU saturation and often cleared as soon as load dropped, such as when alt-tabbing or opening an in-game menu. That pattern strongly suggested the new scheduling behavior was mishandling GPU job fairness or runtime accounting under pressure, starving or stalling important foreground work. A small `min_vruntime` fix reduced the worst lockups in brief tests, but it did not fully solve the stutter. Because the regression surfaced just days before release, maintainers judged it too risky to keep debugging in place. Linus Torvalds and DRM developers backed the safer option: revert the FAIR default and restore FIFO for Linux 7.2, then continue profiling and fixing the fair scheduler for a later kernel. That is why a highly anticipated scheduler update ended up causing severe gaming freezes right before release.

3 articles · Updated · OMG! Ubuntu! · Aug 16

Linux kernel 7.2 is out after a 9-week cycle, bringing cache-aware scheduling, ext4 speedups and a broad set of laptop, peripheral and networking driver updates.
Cache-aware scheduling keeps related threads on cores sharing cache to cut cache bouncing, while pipe locking changes lift performance 6% to 28% and tighter memory reclaim can boost some MongoDB workloads by about 30%.
Ext4 removes lock contention in fast commits, a shared IOMAP fix adds about 5% to small random 4K NVMe reads, and other filesystems also gained speedups, including exFAT write gains of up to 87%.
More than 13,000 lines of legacy i486 emulation code were removed, along with AppleTalk and old graphics and ARCnet drivers, while a fairer GPU scheduler was reverted late over AMD regression reports.
Roughly 5% of commits carried an AI-related assisted-by tag, and the release opens questions for Ubuntu 26.10, which may still choose Linux 7.2 or move to 7.3 under Canonical's latest-kernel policy.