Linux 7.3-rc1 Released, Tree Hits 41 Million Lines
Linux 7.3-rc1 is live. Linus Torvalds tagged the first release candidate of the new cycle on Sunday at 20:34 UTC, closing the merge window and handing the tree to the testers. The stats are in: roughly 10,000 commits, 53 new files, and a total kernel size of approximately 40.98 million lines.
Torvalds' announcement was characteristically blunt. "Nothing really stands out — except for the fact that it's big," he wrote. "It's not the biggest rc1 we've ever had, but it's certainly up there, at least in number of commits."
The AMD Register Dump Factor
The culprit is familiar. The AMD DCN6 register headers account for about a third of the entire diff. Yes, another wall of #defines for hardware definitions. Keep in mind that if you mask out the DCN6 block, things look "pretty normal" compared to recent cycles. The merge window added +9,260 lines and removed 1,737. The tree continues to grow, line by line.
Torvalds also mentioned a personal snag during the release process. He performed a system upgrade mid-merge window and spent time chasing an issue it caused. Everything resolved by the time rc1 was tagged, but the detour was real enough to warrant a mention.
Apple Silicon Thunderbolt and Power Management
On the actual functionality front, the news for Apple users is the most significant. A 19-patch series by Sven Peter lands initial USB4 and Thunderbolt support for M1, M2, and M3 SoCs. The patches add a Thunderbolt switch driver, Apple USB4/Thunderbolt NHI, ring interrupt configuration, and DROM reading from the device tree.
There's also a new Apple PMGR driver for misc power controls. According to the developer, it reportedly saves roughly a watt of power during s2idle on M1 Pro, M1 Max, and M1 Ultra chips. Marginal? Sure. Every watt helps for battery life on MacBooks.
KVM Overhaul, Rust Drivers, and Thermal Improvements
KVM gets a major update with a 45-patch series by Ackerley Tng for guest_memfd in-place conversion. The work includes per-gmem attributes, private/shared memory APIs, SEV/TDX support, and a set of selftests. If you're running confidential computing workloads on AMD SEV or Intel TDX, this series is going to matter to you.
Rust kernel development keeps marching forward. Danilo Krummrich contributed patches tying DMA allocations to device bound lifetimes and managing debugfs file bindings in Rust. The language-based driver work continues to chip away at the device driver surface.
Intel CPU owners get directed package thermal interrupts for finer-grained thermal throttling. Generic CPPC display support is also introduced, depending only on standardized fields, which helps AMD's existing implementation.
The release covers updates across x86, ARM, ARM64, RISC-V, MIPS, PowerPC, s390, Alpha, and LoongArch, among others. A full subsystem list shows Christian Brauner, Ingo Molnar, and Dave Airlie handling the bulk of their respective trees, with Rafael Wysocki wrapping up ACPI and power management changes.
The typical cadence is two weeks for the merge window, followed by six weeks of RCs. With rc1 in the bag, you can expect roughly six more release candidates before stabilization. Linux 7.3 is expected to land in mid-to-late October, likely around October 18 or October 25.
Linux kernel 7.3-rc1 released
Linux kernel version 7.3-rc1 is now available:
Full source: https://git.kernel.org/torvalds/t/linux-7.3-rc1.tar.gz
Patch: https://git.kernel.org/torvalds/p/v7.3-rc1/v7.2
You can view the summary of the changes at the following URL:
https://git.kernel.org/torvalds/ds/v7.3-rc1/v7.2
