Linus Torvalds announced Linux kernel 7.2, bringing improvements across scheduling, filesystems, networking, virtualization, memory management, security, and hardware support.
One interesting addition is cache-aware load balancing in the Linux scheduler. The scheduler can try to keep processes sharing resources within the same cache domain, potentially improving performance by reducing unnecessary cache movement between CPUs.
Memory management sees several notable changes. The ongoing rework of the swap subsystem further unifies handling of anonymous and shared-memory folios while reducing its memory overhead. According to developers, static metadata overhead is now close to zero, with some workloads seeing slightly improved performance.
Btrfs is another major beneficiary of the Linux 7.2 cycle. Large folios are now enabled by default, and support for much larger folios up to 2 MB has been introduced as an experimental option. Meanwhile, XFS’s zoned-storage support, first introduced in Linux 6.15, is no longer marked experimental.
Elsewhere in storage, Linux 7.2 introduces the new dm-inlinecrypt Device Mapper target for block devices that perform inline encryption. NFS also raises its default transfer block size to 4 MB on systems with at least 16 GB of RAM.
The in-kernel SMB server gains support for files stored in compressed form, along with compression for data transferred over the network. NTFS has meanwhile received additional protection against various forms of corrupted on-disk metadata and can now handle Windows-native symbolic links.
On the networking side, MultiPath TCP can now use up to 64 subflows, up from the previous limit of eight. Work also continues on reducing dependency on the global rtnl_lock, part of a broader effort to make the Linux networking stack scale better on larger systems.
Regarding BPF, hash maps can now be created with a resizable implementation instead of a fixed bucket count at creation. The previous five-parameter limit for BPF functions and kfuncs has been lifted by allowing additional arguments to be passed through the stack. The same BPF program can now be attached efficiently to multiple tracepoints.
Virtualization improvements include support in KVM for Intel Mode-Based Execution Control (MBEC) and AMD Guest-Mode Execution Trap functionality. Both provide finer control over executable permissions inside virtual machines and can significantly reduce the need for guests to trap back into the host for permission-related operations.
For Intel TDX systems, Linux 7.2 introduces infrastructure for managing the TDX software module, including the ability to replace it on a running system.
Rust support continues to expand across the kernel, with IBM’s s390 architecture joining the list capable of building Rust kernel code. The kernel source tree now includes the Rust zerocopy crate, which provides low-cost memory-manipulation primitives and helps isolate unsafe code.
Security-related work includes an expansion of Landlock, which can now restrict the use of UDP sockets. The Integrity Measurement Architecture can also export and remove measurement data from kernel memory, potentially freeing significant amounts of memory on systems that accumulate large measurement logs.
On the architecture side, more remnants of i486-era support have disappeared. This includes over 13,000 lines of old floating-point emulation code for processors without a hardware FPU. PowerPC’s hardware-optimized MD5 implementation has also been removed.
A few long-obsolete networking hardware and protocols are gone too, including support for various ISA and PCMCIA ARCnet devices, old PCMCIA Bluetooth adapters, additional ATM code, and AppleTalk. The kernel has also deprecated the AF_ALG mechanism with a view toward its possible future removal.
Developers building the kernel gain a useful new tool. Linux 7.2 adds a make sbom target that generates a configuration-specific Software Bill of Materials using SPDX information from the kernel source. Only files compiled for the selected configuration are included, making the resulting SBOM specific to the generated kernel build.
At the same time, LLVM 17.0.1 is now the minimum supported LLVM release for building the kernel.
As usual, Linux 7.2 also comes with a large amount of new hardware enablement. Among the additions are support for Realtek 8922AU USB wireless adapters, Virtio CAN interfaces, OneXPlayer handheld controllers, newer Wacom devices, additional AMD image-signal processors, USB4STREAM-capable hardware, and a long list of new sensors, power controllers, audio codecs, SoC components, PHYs, and other devices.
Linux 7.2 is available for download at kernel.org. Rolling-release distribution users will receive the update first, with broader availability expected in the coming weeks.
