# Process replay tests

Process replay is a tool for creating a diff of generated kernels between two commits. By default, process replay doesn't assert kernel diffs.

Refactor and speedup PRs must enable the assert by including `[pr]` in the pull request title.

Note that process replay [early stops when over 20% of kernels change, for speed.](https://github.com/tinygrad/tinygrad/pull/5480).

## Running locally

To run process replay locally:

(optional: clear previous process replay runs with `test/external/process_replay/reset.py`)

1. Run tests with `CAPTURE_PROCESS_REPLAY=1` in your branch. This will pickle process inputs to CACHEDB.
2. Checkout master
3. Run `test/external/process_replay/process_replay.py`

For reference, see `test/external/process_replay/local.sh`.