Arm has submitted initial patches to the Linux kernel to support the upcoming TLBI Domains (TLBID) feature. This technology aims to reduce system overhead during TLB invalidation operations on high-core-count processors, improving performance for large-scale multi-core Arm systems.
The TLBID mechanism allows the operating system to target TLB invalidation to specific CPU cores rather than performing a full-system operation. The kernel will track which cores a process has run on and send invalidation instructions only to those relevant processors, minimizing synchronization and communication overhead.
The feature is primarily designed for high-core-count Arm server processors. While the potential for performance gains exists, Arm has not yet released specific performance test data, meaning the actual impact remains to be verified through future hardware and software implementations.
Implementation of TLBID on the ARM64 architecture requires support from the compilation toolchain. Developers must use LLVM 23 or newer, or GNU Binutils 2.46 or newer. The patches are currently in the early stages of development, with further work required across architecture specifications and software support.
