Linux 7.3 released with ext4 speedups, low-VRAM AMD GPU fixes, cgroup scheduling rework

Linus Torvalds announced Linux 7.3, which is expected to become the next Long Term Support kernel. The release includes better memory management for AMD GPUs with limited VRAM through priority-based eviction, a reworked cgroup CPU scheduler with a new default 'concur' mode, and faster ext4 direct I/O. It also adds initial drivers for the 2026 Steam Controller and MSI Claw, plus early bring-up support for Apple M3 Pro/Max/Ultra chips.

What changes in Linux 7.3

• AMD GPU VRAM management: New eviction logic allows the kernel to remove unprotected background data from VRAM to make room for higher-priority tasks with protected memory requests. Valve's Natalie Vock implemented this; testing with Indiana Jones and the Great Circle showed playable performance on an 8GB GPU with settings pushing toward 9GB VRAM usage.
• cgroup CPU scheduling: The scheduler now allocates CPU time between process groups and moves cgroups to a single run queue. New concur mode is now default, with fallback to previous behavior available. Scheduler maintainer Peter Zijlstra's earlier tests showed minimum frame rates improving from 3.8fps to 20.6fps under heavy background load.
• ext4 performance: Parallel direct I/O writes, fallocate(), and small direct reads are faster. A buffered-write regression was fixed. ByteDance testing on PCIe Gen5 NVMe showed 4K random reads improving from 1.92M to 2.19M IOPS, with higher gains using io_uring.
• Hardware support additions: 2026 Steam Controller driver, MSI Claw gamepad driver (both Valve contributions), HyperX QuadCast 2 mute reporting, Logitech PRO X Wireless headset mic hotplug, HID++ 2.0 reprogrammable buttons, Pioneer DJ DJM-S11 USB audio, TUXEDO laptop internal mics, Realtek 8922DE/8922DE-VS Wi-Fi, additional ASUS motherboard sensors.
• Apple Silicon: Early bring-up for M3 Pro/Max/Ultra (M3 base support arrived in 7.2). ksmbd gains optional Apple Time Machine support. AMDGPU DC handles Apple Studio Display's dual-stream 5K panel correctly as single display.
• Other: sched_ext enables BPF-based sub-schedulers for cgroups, RWF_DONTCACHE for block devices, new AES library APIs, up to 5x faster btrfs fsync in some cases, FUSE buffer pools with zero-copy over io_uring, Nouveau NVDEC support for Vulkan Video in NVK, Rust PowerPC support.

Why it matters

With 18,765 non-merge commits from over 3,000 developers including 807 first-time contributors, this release sets a record for new developer participation. Expected to become the next LTS kernel, these changes will reach Ubuntu 26.10 immediately and Ubuntu 26.04 LTS users through HWE updates in early 2027.