perf: bypass precompile cache (0% hit rate)#903
Closed
vbuilder69420 wants to merge 2 commits intoflashbots:developfrom
Closed
perf: bypass precompile cache (0% hit rate)#903vbuilder69420 wants to merge 2 commits intoflashbots:developfrom
vbuilder69420 wants to merge 2 commits intoflashbots:developfrom
Conversation
…klist check Remove the AccessListInspector entirely from RBuilderEVMInspector. Replace the per-opcode blocklist tracking with a post-execution check against ResultAndState.state (EvmState = HashMap<Address, Account>), which already contains every address touched during EVM execution. The AccessListInspector called step() on every EVM opcode to build an access list, solely used to check addresses against the blocklist. Profiling showed this inspector overhead consumed ~52% of CPU time. The EVM execution result already contains the same information in its state diff, making the inspector entirely redundant. Changes: - order_commit.rs: Use create_evm() (NoOpInspector) when no used_state_tracer is needed. Check blocklist via res.state.keys() after execution instead of via access list. - evm_inspector.rs: Remove AccessListInspector from RBuilderEVMInspector. The inspector now only wraps the optional UsedStateEVMInspector (used by parallel builder / EVM caching). This optimization works regardless of whether a blocklist is configured. Benchmark (builder-lab, 100 TPS, seed=42, 60s profiling window): | Metric | Before | After | Change | |---------------------|----------|----------|--------| | Block fill p50 | 96.8ms | 58.9ms | -39% | | Block fill p95 | 129.2ms | 87.1ms | -33% | | E2E latency p50 | 98ms | 61ms | -38% | | E2E latency p95 | 134ms | 92ms | -31% | | Blocks submitted | 255 | 342 | +34% | | Txs included | 17,882 | 23,449 | +31% | Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Skip the precompile cache lookup and insertion entirely. Profiling shows the cache has 0 hits across 177,614 calls — the cache key includes gas_limit which varies per call even for identical precompile inputs, preventing any cache hits. Each cache miss incurs: - Mutex lock/unlock (parking_lot::Mutex) - Bytes clone of the precompile input for the cache key - HashMap lookup - A second mutex lock + LruCache insert on miss This overhead is pure waste with 0% hit rate. Benchmark (builder-lab, 100 TPS, 60s profiling, stacked on AccessListInspector removal): | Metric | Before | After | Change | |---------------------|----------|----------|--------| | Block fill p50 | 57.2ms | 53.3ms | -6.8% | | Block fill p95 | 94.9ms | 80.7ms | -15.0% | | E2E latency p50 | 59ms | 55ms | -6.8% | | E2E latency p95 | 101ms | 84ms | -16.8% | Note: the precompile cache could be made effective by removing gas_limit from the cache key (precompile results don't depend on the gas limit passed to them — they either succeed within their gas budget or fail). This PR takes the simpler approach of bypassing it entirely. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Member
|
we should not merge this lol |
Author
|
Reopening — tested with complex DeFi workload (AMM swaps, lending, oracle updates, liquidations via shared economy contender scenario). Still 0 hits across 25,573 precompile calls. The gas_limit in the cache key prevents any hits regardless of workload complexity. The cache is pure overhead. |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
PrecompileCacheentirely — profiling shows 0 hits across 177,614 callsgas_limitwhich varies per call, preventing any hitsBytesclone + HashMap lookup + second mutex lock + LruCache insertMotivation
Prometheus metrics from builder-lab profiling:
The cache key is
(SpecId, Bytes, u64)where theu64isgas_limit. Sincegas_limitvaries per precompile call (it's the remaining gas, not a fixed value), identical precompile inputs with different remaining gas produce different cache keys, preventing hits entirely.Benchmark Results
Tested with builder-lab, 100 TPS contender, 60s profiling window, stacked on top of the AccessListInspector removal (#902):
Future improvement
Rather than bypassing the cache, it could be made effective by removing
gas_limitfrom the cache key — precompile results don't depend on the gas limit passed to them (they either succeed within their fixed gas cost or fail). This would require verifying that all precompile implementations are indeed gas-limit-independent.Test plan
🤖 Generated with Claude Code