SIMD-0458

TL;DR

This proposal removes the use of statically defined compute unit (CU) costs for Simple Vote transactions and instead accounts for them in the same way as normal transactions when enforcing block CU limits. This also renders the Vote CU limit obsolete. Because this change affects consensus behavior, it must be gated behind a feature flag.

Summary

This proposal removes the use of statically defined compute unit (CU) costs for Simple Vote transactions and instead accounts for them in the same way as normal transactions when enforcing block CU limits. This also renders the Vote CU limit obsolete. Because this change affects consensus behavior, it must be gated behind a feature flag.

Motivation

Simple Vote transactions currently reserve a fixed, statically defined number of compute units for cost tracking, based on the assumption that the Vote program, as a builtin program, has a static execution CU cost. However, SIMD-0387 specifies that the Vote program will be removed from builtin cost modeling. As a result, the cost of Simple Vote transactions should no longer rely on static CU assumptions and should instead be calculated in the same manner as other transactions.

Key Changes

• Stop using statically defined CU values for Simple Vote transactions.
• Calculate the cost of Simple Vote transactions using the same cost model and accounting path as normal transactions.
• Remove vote CU limit.

Impact

The impact on cost consuming/tracking, and CU reserving for simple vote can be summarized in table: | |Total consumed CUs | Total reserved CUs| |:--|:--|:--| |Current |3428 |3428| |Proposed |3428* |19812** | - Cost tracking: The impact is expected to be minimal, as the actual executed CU consumption of Simple Vote transactions is identical to the previously statically defined value for the vast majority of votes. CU consumption will only change for unusual vote transactions that still classify as simple votes (e.g. two signatures, or additional writable accounts), or unusually large vote accounts. [ * ]statically define CUs for simple vote includes 1 signature (720 CU), 2 write locks (600 CU), 1 vote instruction which has 2,100 CU, and 8 CU to load small accounts, total 3428 CU. All components stay same except the CU for loaded accounts data size may change, which is a small part overall CUs. - Block production: [ ** ] Under the current cost model, Simple Vote transactions may have higher estimated CUs ( about 16K additional CUs) due to inclusion of default account data loading costs. For block-packing strategies that reserve CUs upfront and refund unused CUs after execution, this may result in larger initial CU reservations for Simple Vote transactions, followed by refunds. This effect is specific to such “reserve-then-refund” packing strategies.

Security Considerations

N/A