Linux 6.15 will bring support for 8,192 cores in the Turbostat CPU monitoring utility, if you happen to have such a system (via Phoronix). The change was driven by an HPE (Hewlett-Packard Enterprise) engineer who faced an issue with their unnamed 1,152-core system since Turbostat wasn't designed to handle more than 1,024 cores/threads. We currently aren't aware of any server CPU configurations that can exceed this limit (in terms of physical cores), so this may be a custom or next-generation solution from Intel or AMD. The utility currently only supports x86 processors, which seemingly rules out an Arm system from causing the issue.
Turbostat is a Linux command-line utility provided by the kernel-tools package and is baked into most distributions. It's a monitoring utility that reports clock speeds, idle power-state statistics, temperature, etc., on x86-based processors. This is important information, as we can infer that the 1,152 core system is likely an Intel/AMD solution. Likewise, a while back, Ampere's 384-core servers exposed a maximum core count limitation with the ARM64 Linux kernel, which only supported up to 256 cores.
