Definition
Plain language
A small, central piece of code that does one critical job — on a graphics chip it's a fast math routine, and in a proof checker it's the trusted core that verifies every step.
As stated in the literature
On a GPU, a compute routine implementing a primitive operation (e.g., a CUDA kernel); writing fast custom kernels is a frequent optimization target for self-improving agents and is benchmarked by KernelBench. In a proof assistant like Lean, the kernel is instead the small, heavily-scrutinized trusted core that mechanically checks each proof step. Distinct from an OS kernel.
Also called: kernels, CUDA kernel, GPU kernel
Why it matters: Faster kernels can dramatically speed up training and inference, making them a prime target for agents that optimize their own performance.
For example, a custom kernel might multiply two matrices on a GPU far faster than the default code by squeezing the most out of the chip.
Heard on the show
“The other is AI research and development tasks, including kernel optimization on KER-nel-bench and code generation on big-CODE-bench.”Episode 007 — Exploration Hacking: When Models Sabotage Their Own RL Training