inclusion: bench enact_candidate weight

[ordian]

On top of #5082.

Background

Previously, before #3479, we would include the cost enacting the candidate into the cost of processing a single bitfield. Now it is different, although the benchmarks seems to be not-up-to date.
Including the cost of enacting a candidate into a processing a single bitfield cost was incorrect, since we multiple that by the number of bitfields we have. Instead, we should separate calculate the cost of processing a single bitfield without enactment, and multiple the cost of enactment by the actual number of processed candidates (which is limited by the number cores, not validators).

Bench

Previously, the weight of enact_candidate was calculated manually (without a benchmark) and then neglected:

polkadot-sdk/polkadot/runtime/parachains/src/inclusion/mod.rs

Line 584 in dd48544

let _weight = Self::enact_candidate(

In this PR, we have a benchmark for it and it's based on the number of ump and sent hrmp messages as well as whether the candidate has a runtime upgrade (new_validation_code).
The differences from the previous attempt paritytech/polkadot#6929 are that

• we don't include the cost of enactment into the cost of processing a backed candidate.
  The reason for it is that enactment happens not in the same block as backing (typically the next one), since we process bitfields before backing votes.
• we don't take into account the size of the runtime upgrade, the benchmark weight doesn't seem to depend much on it, but rather whether there was one or not.

Similarly to the previous attempt, we don't account for dmp messages (fixed cost). Also we don't account properly for received hrmp messages (hrmp_watermark) because the cost of it depends on the runtime state and can't be statically deduced in the benchmark (unless we pass the information about channels as benchmark u32 arguments).

The total weight cost of processing a parainherent now includes the cost of enactment of each candidate, but we don't do filtering based on that (because we enact after processing bitfields and making other changes to the storage).

Numbers

Reads = 7 + (0 * u) + (3 * h) + (8 * c)
Writes = 10 + (1 * u) + (3 * h) + (7 * c)

In addition, there is a fixed cost of a few of ms (!) per candidate.

This might result a full block slightly overflowing its weight with 200 enacted candidates, which in turn could prevent non-mandatory transactions from being included in a block.

Given our modest limits on max ump and hrmp messages:

  maxUpwardMessageNumPerCandidate: 16
  hrmpMaxMessageNumPerCandidate: 10

and the fact that runtime upgrades are can't happen very frequently (validation_upgrade_cooldown), we might only go over the limits in case of many disputes.

TODOs:

• Fix the overweight test
• Generate the weights for Westend and Rococo
• PRDoc

[ordian]

bot bench polkadot-pallet --pallet=polkadot_runtime_parachains::inclusion --runtime=westend
bot bench polkadot-pallet --pallet=polkadot_runtime_parachains::inclusion --runtime=rococo
bot clean

[command-bot]

@ordian Command "$PIPELINE_SCRIPTS_DIR/commands/bench/bench.sh" --subcommand=pallet --runtime=westend --target_dir=polkadot --pallet=polkadot_runtime_parachains::inclusion has finished. Result:

HttpError: Not Found
HttpError: Not Found
    at /app/node_modules/@octokit/request/dist-node/index.js:86:21
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async sendRequestWithRetries (/app/node_modules/octokit-auth-probot/node_modules/@octokit/auth-app/dist-node/index.js:466:12)
    at async Job.doExecute (/app/node_modules/bottleneck/light.js:405:18)

[command-bot]

@ordian Command "$PIPELINE_SCRIPTS_DIR/commands/bench/bench.sh" --subcommand=pallet --runtime=rococo --target_dir=polkadot --pallet=polkadot_runtime_parachains::inclusion has finished. Result:

HttpError: Not Found
HttpError: Not Found
    at /app/node_modules/@octokit/request/dist-node/index.js:86:21
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async sendRequestWithRetries (/app/node_modules/octokit-auth-probot/node_modules/@octokit/auth-app/dist-node/index.js:466:12)
    at async Job.doExecute (/app/node_modules/bottleneck/light.js:405:18)

[alindima]

LGTM, nice work!

[sandreim]

I think we should get rid of tracking the proof size in polkadot-runtime-parachains, the BlockWeight proof size limit is set to u64::MAX on the relaychain. It only makes sense for parachains to measure it.

[ordian]

I agree, but it is orthogonal to this PR and I'd leave to for the later refactoring aka the long-term fix.

[eskimor]

@ordian @sandreim No, we actually use this to ensure we don't overfill the block with transactions.

[paritytech-cicd-pr]

The CI pipeline was cancelled due to failure one of the required jobs.
Job name: test-linux-stable 1/3
Logs: https://gitlab.parity.io/parity/mirrors/polkadot-sdk/-/jobs/7178925