# Weight Generation
To generate weights for a runtime.
Weights generation is using self-hosted runner which is provided by Parity CI, the rest commands are using standard
GitHub runners on `ubuntu-latest` or `ubuntu-20.04`.
Self-hosted runner for benchmarks (`parity-weights`) is configured to meet requirements of reference
hardware for running validators
https://docs.polkadot.com/infrastructure/running-a-validator/requirements/#minimum-hardware-requirements
In a PR run the actions through comment:
```sh
/cmd bench --help # outputs the actual usage documentation with examples and supported runtimes
# or
/cmd --help # to see all available commands
```
To regenerate all weights (however it will take long,
so don't do it unless you really need it), run the following command:
```sh
/cmd bench
```
To generate weights for all pallets in a particular runtime(s), run the following command:
```sh
/cmd bench --runtime kusama polkadot
```
For Substrate pallets (supports sub-modules too):
```sh
/cmd bench --runtime dev --pallet pallet_asset_conversion_ops
```
> **📝 Note**: The action is not being run right-away, it will be queued and run in the next available runner.
> So might be quick, but might also take up to 10 mins (That's in control of Github).
> Once the action is run, you'll see reaction 👀 on original comment, and if you didn't pass `--quiet` -
> it will also send a link to a pipeline when started, and link to whole workflow when finished.
>
> **📝 Note**: It will try keep benchmarking even if some pallets failed, with the result of failed/successful pallets.
>
> If you want to fail fast on first failed benchmark, add `--fail-fast` flag to the command.
---
This way it runs all possible runtimes for the specified pallets, if it finds them in the runtime
```sh
/cmd bench --pallet pallet_balances pallet_xcm_benchmarks::generic pallet_xcm_benchmarks::fungible
```
If you want to run all specific pallet(s) for specific runtime(s), you can do it like this:
```sh
/cmd bench --runtime bridge-hub-polkadot --pallet pallet_xcm_benchmarks::generic pallet_xcm_benchmarks::fungible
```
> **💡Hint #1** : Sometimes when you run too many commands, or they keep failing and you're rerunning them again,
> it's handy to add `--clean` flag to the command. This will clean up all yours and bot's comments in PR relevant to
> /cmd commands.
```sh
/cmd bench --runtime kusama polkadot --pallet=pallet_balances --clean
```
> **💡Hint #2** : If you have questions or need help, feel free to tag @paritytech/opstooling (in github comments)
> or ping in [matrix](https://matrix.to/#/#command-bot:parity.io) channel.