core: attempt at alternative tx-level prefetcher

core/blockchain.go

@@ -1793,9 +1793,8 @@ func (bc *BlockChain) insertChain(chain types.Blocks, setHead bool) (int, error)
 		// transactions and probabilistically some of the account/storage trie nodes.
 		var followupInterrupt atomic.Bool
 		if !bc.cacheConfig.TrieCleanNoPrefetch {
-			if followup, err := it.peek(); followup != nil && err == nil {
+			followup := block
 			throwaway, _ := state.New(parent.Root, bc.statedb)
-
 			go func(start time.Time, followup *types.Block, throwaway *state.StateDB) {
 				// Disable tracing for prefetcher executions.
 				vmCfg := bc.vmConfig
@@ -1808,7 +1807,6 @@ func (bc *BlockChain) insertChain(chain types.Blocks, setHead bool) (int, error)
 				}
 			}(time.Now(), followup, throwaway)
 		}
-		}
 
 		// The traced section of block import.
 		res, err := bc.processBlock(block, statedb, start, setHead)

core/state_prefetcher.go

@@ -53,8 +53,10 @@ func (p *statePrefetcher) Prefetch(block *types.Block, statedb *state.StateDB, c
 		signer       = types.MakeSigner(p.config, header.Number, header.Time)
 	)
 	// Iterate over and process the individual transactions
-	byzantium := p.config.IsByzantium(block.Number())
-	for i, tx := range block.Transactions() {
+	txs := block.Transactions()
+	// Skip the first third of transactions, prefetch the latter two thirds of the transactions
+	for i := (len(txs) * 2) / 3; i < len(txs); i++ {
+		tx := txs[i]
 		// If block precaching was interrupted, abort
 		if interrupt != nil && interrupt.Load() {
 			return
@@ -68,14 +70,6 @@ func (p *statePrefetcher) Prefetch(block *types.Block, statedb *state.StateDB, c
 		if err := precacheTransaction(msg, p.config, gaspool, statedb, header, evm); err != nil {
 			return // Ugh, something went horribly wrong, bail out
 		}
-		// If we're pre-byzantium, pre-load trie nodes for the intermediate root
-		if !byzantium {
-			statedb.IntermediateRoot(true)
-		}
-	}
-	// If were post-byzantium, pre-load trie nodes for the final root hash
-	if byzantium {
-		statedb.IntermediateRoot(true)
 	}
 }