feat: disable parallel when txs count is low

cmd/geth/main.go

@@ -172,6 +172,7 @@ var (
 		utils.ParallelTxFlag,
 		utils.ParallelTxUnorderedMergeFlag,
 		utils.ParallelTxNumFlag,
+		utils.ParallelThresholdFlag,
 		utils.ParallelTxDAGFlag,
 		utils.ParallelTxDAGFileFlag,
 		utils.ParallelTxDAGSenderPrivFlag,

cmd/utils/flags.go

@@ -1112,6 +1112,12 @@ Please note that --` + MetricsHTTPFlag.Name + ` must be set to start the server.
 		Category: flags.VMCategory,
 	}
 
+	ParallelThresholdFlag = &cli.IntFlag{
+		Name:     "parallel.threshold",
+		Usage:    "Threshold of transaction count to trigger parallel execution, only valid in parallel mode (runtime calculated, no fixed default value)",
+		Category: flags.VMCategory,
+	}
+
 	ParallelTxDAGFlag = &cli.BoolFlag{
 		Name:     "parallel.txdag",
 		Usage:    "Enable the experimental parallel TxDAG generation, only valid in full sync mode (default = false)",
@@ -2034,6 +2040,10 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 		cfg.ParallelTxNum = ctx.Int(ParallelTxNumFlag.Name)
 	}
 
+	if ctx.IsSet(ParallelThresholdFlag.Name) {
+		cfg.ParallelThreshold = ctx.Int(ParallelThresholdFlag.Name)
+	}
+
 	if ctx.IsSet(ParallelTxDAGFlag.Name) {
 		cfg.EnableParallelTxDAG = ctx.Bool(ParallelTxDAGFlag.Name)
 	}

core/blockchain.go

@@ -539,6 +539,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, genesis *Genesis
 		log.Info("Parallel V2 enabled", "parallelNum", ParallelNum())
 	} else {
 		bc.processor = NewStateProcessor(chainConfig, bc, engine)
+		bc.serialProcessor = bc.processor
 	}
 	// Start future block processor.
 	bc.wg.Add(1)
@@ -1936,9 +1937,15 @@ func (bc *BlockChain) insertChain(chain types.Blocks, setHead bool) (int, error)
 
 			statedb.SetExpectedStateRoot(block.Root())
 
+			// Decide the enabling of parallelExec
+			invalidParallelConfig := bc.vmConfig.TxDAG == nil && bc.vmConfig.EnableParallelUnorderedMerge
+			lowTxsNum := bc.vmConfig.ParallelThreshold >= block.Transactions().Len()
+			useSerialProcessor := invalidParallelConfig || lowTxsNum || !bc.vmConfig.EnableParallelExec
+
 			// Process block using the parent state as reference point
 			pstart = time.Now()
-			if bc.vmConfig.TxDAG == nil && bc.vmConfig.EnableParallelUnorderedMerge {
+
+			if useSerialProcessor {
 				receipts, logs, usedGas, err = bc.serialProcessor.Process(block, statedb, bc.vmConfig)
 			} else {
 				receipts, logs, usedGas, err = bc.processor.Process(block, statedb, bc.vmConfig)

core/pevm_processor.go

@@ -35,8 +35,12 @@ func newPEVMProcessor(config *params.ChainConfig, bc *BlockChain, engine consens
 		unorderedMerge: bc.vmConfig.EnableParallelUnorderedMerge,
 	}
 	initParallelRunner(bc.vmConfig.ParallelTxNum)
+	if bc.vmConfig.ParallelThreshold == 0 {
+		bc.vmConfig.ParallelThreshold = ParallelNum()
+	}
 	log.Info("Parallel execution mode is enabled", "Parallel Num", ParallelNum(),
-		"CPUNum", runtime.GOMAXPROCS(0), "unorderedMerge", processor.unorderedMerge)
+		"CPUNum", runtime.GOMAXPROCS(0), "unorderedMerge", processor.unorderedMerge,
+		"parallel threshold", bc.vmConfig.ParallelThreshold)
 	return processor
 }
 

core/vm/interpreter.go

@@ -36,6 +36,7 @@ type Config struct {
 	ExtraEips                    []int               // Additional EIPS that are to be enabled
 	EnableParallelExec           bool                // Whether to execute transaction in parallel mode when do full sync
 	ParallelTxNum                int                 // Number of slot for transaction execution
+	ParallelThreshold            int                 // Threshold of transactions number to trigger parallel process
 	OptimismPrecompileOverrides  PrecompileOverrides // Precompile overrides for Optimism
 	EnableOpcodeOptimizations    bool                // Enable opcode optimization
 	TxDAG                        types.TxDAG

eth/backend.go

@@ -227,6 +227,7 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
 			EnableParallelExec:           config.ParallelTxMode,
 			EnableParallelUnorderedMerge: config.ParallelTxUnorderedMerge,
 			ParallelTxNum:                config.ParallelTxNum,
+			ParallelThreshold:            config.ParallelThreshold,
 			EnableOpcodeOptimizations:    config.EnableOpcodeOptimizing,
 		}
 		cacheConfig = &core.CacheConfig{

eth/ethconfig/config.go

@@ -221,11 +221,11 @@ type Config struct {
 
 	ParallelTxMode           bool // Whether to execute transaction in parallel mode when do full sync
 	ParallelTxNum            int  // Number of slot for transaction execution
+	ParallelThreshold        int  // threshold to trigger parallel execution
 	EnableOpcodeOptimizing   bool
 	EnableParallelTxDAG      bool
 	ParallelTxDAGFile        string
 	ParallelTxUnorderedMerge bool // Whether to enable unordered merge in parallel mode
-
 }
 
 // CreateConsensusEngine creates a consensus engine for the given chain config.