The Whole of PyTorch on One Page

The Whole of PyTorch on One Page

This series maps the entire PyTorch framework, from the Python API down to the kernels and hardware. Part 0 provides a high-level overview, revealing that the Python layer is tiny compared to the 235 MB of compiled C++ underneath. It introduces the dispatcher, kernels, memory management, and the two clocks (CPU and GPU), promising a floor-by-floor exploration in subsequent parts.

The Python you write all day is the smallest layer of it.
  1. bonoboTP

    Not bad, but Claude is not quite good yet for writing these explainers. We should try again in a few months with newer models.

  2. Ask12j

    Lol, a yaml file for function signatures of which to generate a giant switch statement.

    The "compiler" dynamo part is also a hack that calls real compilers like gcc and Triton.

    It is a big bowl of spaghetti.

  3. 4b11b4

    Can tell it's garbage just from the first figures caption

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2026-08-11