Notes for EVM Repricing Workgroup (15th January 2025)

Summary

The meeting focused on resource pricing strategies for Ethereum, with discussions on short-term and medium to long-term changes.

Marek presented a gas pricing tool that identified significant differences in gas costs across clients, highlighting bottlenecks.
Jacek Glen shared a gas cost estimator project, proposing adjustments to opcode and precompile costs.
Ansgar Dietrichs discussed potential repricing strategies, emphasizing the need for metrics to assess real-world impacts.
The group considered the implications of gas smuggling and state repricing, with Toni Wahrstätter suggesting block-level state warming could yield up to 15% efficiency gains.

The meeting concluded with plans to further explore these topics in future sessions.

Jacek Glen from Imapp to share the updated results for Gas Cost Estimator
(unassigned) to explore the impact of different repricing approaches on Mainnet transaction throughput
(unassigned) to prepare a EIP proposal for adjusting the pricing of one or more operations based on the benchmark results
Possibly Marek / Ben Adams from Nethermind to investigate the feasibility and implications of using gas smuggling to decouple gas refunds from block gas usage
Davide Crapis to schedule follow-up call to discuss medium-term gas pricing roadmap
Toni Wahrstätter to share his work on block-level state warming

Davide Crapis introduces the working group, explaining its origins and focus on resource pricing, particularly in the context of short-term pricing changes and multi-dimensional pricing mechanisms.
The group aims to apply research to practical scenarios, with a plan to discuss benchmarking work and short-term changes that could be implemented in upcoming forks.
The meeting's agenda includes presentations on initial analysis and multi-dimensional pricing mechanisms, with a focus on keeping discussions concrete and actionable.
The goal is to draft EIPs for short-term changes and eventually work towards more ambitious multi-dimensional changes.

Marek presents a tool developed at Nethermind for gas pricing, which can be used for benchmarking and testing gas limits.
The tool measures the execution time of blocks and can identify bottlenecks, using Engine API requests to simulate real-world scenarios.
Marek highlights the benefits and limitations of the tool, noting that it is less accurate than language-specific benchmarking tools but can still provide valuable insights.
The tool has identified significant differences in gas pricing across clients, which could impact gas limits on L1 and Ethereum-based L2 systems.

Davide Crapis asks Marek about plans to propose changes based on the analysis findings.
Marek confirms that some issues have been addressed between client teams and mentions an upcoming EIP to adjust the cost of a specific operation that was significant.
Ameziane Hamlat thanks Marek for the presentation and shares that their team used the tool to reproduce and improve opcodes, addressing issues raised by the Nethermind report.

Jacek Glen presents the gas cost estimator project, which tests EVM implementations in isolation using specific language native tools.
The project involves generating 50,000 bytecode programs to test opcodes and precompiles under various conditions, with results normalized to current gas costs.
Jacek shares preliminary findings, proposing adjustments to opcode costs based on computational expense, with a focus on arithmetic opcodes and precompiles.
The group discusses the implications of these proposals, including potential impacts on block size and storage costs.

Ansgar Dietrichs introduces the topic of short-term pricing changes, focusing on the strategy for the next few hard forks and specific changes for the upcoming forks.
The group discusses the goals of the initial repricing effort, including harmonizing compute costs and potentially allowing for more compute in the block.
Concerns are raised about the potential increase in block size and the need to balance compute costs with storage costs.
The group considers different approaches to repricing, including using fractional gas costs and increasing the gas limit to offset changes in non-compute operations.
- There was soft consensus that fractional gas or particle gas, might be too radical of a change.
- There was also a suggestion to rebase the price of opcodes to 1 gas, ie the minimum gas unit would be 1 gas and everything else is scaled up from that

Ansgar Dietrichs raises the issue of backwards compatibility and the potential impact on legacy contracts with hard-coded gas values.
The group discusses the challenges of analyzing the breadth of mainnet contracts and the potential risks of breaking existing contracts.
- Ansgar notes that it is not possible to exhaustively check whether a gas reprice will break a contract because there might be code that branches on the gas price.
Ben Adams and others express concerns about increasing prices and the potential for unexpected out-of-gas issues.
The group agrees that while backwards compatibility should be considered, the focus should be on understanding the real-world impact of pricing changes.

The group discusses the potential for limiting pricing changes to newly introduced EOF contracts to incentivize adoption
Danno Ferrin highlights the benefits of EOF in reducing gas introspection and the potential for easier pricing changes
The group considers the trade-offs of limiting changes to EOF, including the risk of slowing down the ecosystem's transition to EOF.
The consensus leans towards applying pricing changes to both legacy and EOF contracts to maximize throughput improvements.

Ben Adams explains the concept of gas smuggling and its impact on block gas usage, suggesting changes to reduce the impact of refunds on block limits.
The group discusses the potential benefits and theoretical implications of gas smuggling, with Barnabe's analysis noted as a reference.
Toni Wahrstätter summarizes his work on block-level state warming, which could provide efficiency gains by treating state slots as warm if they have been touched in previous transactions.
The group considers the potential for multi-block warming and its impact on throughput, with Paweł Bylica raising concerns about the accounting changes.

The group acknowledges the need for further discussion and tooling to understand the real-world impact of proposed pricing changes.
Ansgar Dietrichs emphasizes the importance of metrics in informing decisions and suggests scheduling another call to delve deeper into medium-term changes.
Davide Crapis confirms plans to schedule a follow-up call to continue the discussion.
The meeting concludes with a reminder to consider pricing for ZK proving as part of the long-term strategy.