Commit c8fda4f1 authored by Sergei Shulepov's avatar Sergei Shulepov Committed by GitHub
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paras: `include_pvf_check_statement` rt bench (#4938)



* paras: `include_pvf_check_statement` rt bench

Resolves #4933

This PR adds a benchmark for the `include_pvf_check_statement`
dispatchable. This is a necessary step to make it work without
modifications. That enables us to proceed with testing on Versi.

This introduces 5 new benchmarks. Those measure performance of the
`include_pvf_check_statement` under 2 different conditions:

1. regular vote submission. That's the common case.
2. submission of the last vote. That happens only once and leads to a
   heavy finalization stage.

There are 2 different types of finalization (one for onboarding, one for
upgrading) and there are two outcomes: accepted and rejected. Those 4
are similar but I decided to cover them all and assign the maximum of
all 4. This is to avoid a situation when one of those paths becomes more
heavier than others and opens up an attack venue.

The regular vote submission weight is drastically different from the
submission last vote weight. That's why in case during runtime
finalization was not executed the weight consumed value will be lowered
down to the regular vote submission.

The finalization weight is proportional to the number of "causes", i.e.
the events that caused the PVF pre-checking vote in the first place, and
here we assume that the maximum number of causes is 100.

Theoretically, there is nothing that prevents an adversary to
register/upgrade to more than 100 parachains. In that case, the consumed
weight will be lower than the actual time consumed by the finalization
process. That can enable a DoS vector.

However, practically, it is not very possible. Right now it is very
expensive to call `schedule_para_initialize` because it requires a very
large lock up of funds. Moreover, finalizing a vote with 100 causes
leads to around 31ms time spent. Finalizing more will require more time.
However, finalizing with 200 causes will cause ≈62ms delay. This is not
that bad since even though we had a full block and the adversary tried
to finalize 200 causes it won't be able to even exceed the operational
extrinsic boundary of 250ms and even if so it won't make big difference.

That said, this should be addressed later on, esp. when we enable
parathreads, which will make creating causes easier. One of potential
solutions will be shifting the logic of finalization into
`on_initialize`/`on_finalize`. Another is to create a maximum number of
causes and then reject upgrades or onboardings if that was reached.

* cargo run --quiet --profile=production  --features=runtime-benchmarks -- benchmark --chain=polkadot-dev --steps=50 --repeat=20 --pallet=runtime_parachains::paras --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --header=./file_header.txt --output=./runtime/polkadot/src/weights/runtime_parachains_paras.rs

* cargo run --quiet --profile=production  --features=runtime-benchmarks -- benchmark --chain=kusama-dev --steps=50 --repeat=20 --pallet=runtime_parachains::paras --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --header=./file_header.txt --output=./runtime/kusama/src/weights/runtime_parachains_paras.rs

* cargo run --quiet --profile=production  --features=runtime-benchmarks -- benchmark --chain=westend-dev --steps=50 --repeat=20 --pallet=runtime_parachains::paras --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --header=./file_header.txt --output=./runtime/westend/src/weights/runtime_parachains_paras.rs

* cargo run --quiet --profile=production --features runtime-benchmarks -- benchmark --chain=rococo-dev --steps=50 --repeat=20 --pallet=runtime_parachains::paras --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --header=./file_header.txt --output=./runtime/rococo/src/weights/runtime_parachains_paras.rs

* Fix import error

Co-authored-by: default avatarParity Bot <[email protected]>
Co-authored-by: default avatarRobert Klotzner <[email protected]>
Co-authored-by: default avatarLldenaurois <[email protected]>
parent aa89374d
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