cmd, core: prefetch reads too from tries if requested (#29807)

* cmd/utils, consensus/beacon, core/state: when configured via stub  flag: prefetch all reads from account/storage tries, terminate prefetcher synchronously.

* cmd, core/state: fix nil panic, fix error handling, prefetch nosnap too

* core/state: expand prefetcher metrics for reads and writes separately

* cmd/utils, eth: fix noop collect witness flag

---------

Co-authored-by: Péter Szilágyi <peterke@gmail.com>

cmd/geth/main.go

@@ -156,6 +156,7 @@ var (
 		utils.BeaconGenesisRootFlag,
 		utils.BeaconGenesisTimeFlag,
 		utils.BeaconCheckpointFlag,
+		utils.CollectWitnessFlag,
 	}, utils.NetworkFlags, utils.DatabaseFlags)
 
 	rpcFlags = []cli.Flag{

cmd/utils/flags.go

@@ -604,6 +604,11 @@ var (
 		Usage:    "Disables db compaction after import",
 		Category: flags.LoggingCategory,
 	}
+	CollectWitnessFlag = &cli.BoolFlag{
+		Name:     "collectwitness",
+		Usage:    "Enable state witness generation during block execution. Work in progress flag, don't use.",
+		Category: flags.MiscCategory,
+	}
 
 	// MISC settings
 	SyncTargetFlag = &cli.StringFlag{
@@ -1760,6 +1765,9 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 		// TODO(fjl): force-enable this in --dev mode
 		cfg.EnablePreimageRecording = ctx.Bool(VMEnableDebugFlag.Name)
 	}
+	if ctx.IsSet(CollectWitnessFlag.Name) {
+		cfg.EnableWitnessCollection = ctx.Bool(CollectWitnessFlag.Name)
+	}
 
 	if ctx.IsSet(RPCGlobalGasCapFlag.Name) {
 		cfg.RPCGasCap = ctx.Uint64(RPCGlobalGasCapFlag.Name)
@@ -2190,7 +2198,10 @@ func MakeChain(ctx *cli.Context, stack *node.Node, readonly bool) (*core.BlockCh
 	if ctx.IsSet(CacheFlag.Name) || ctx.IsSet(CacheGCFlag.Name) {
 		cache.TrieDirtyLimit = ctx.Int(CacheFlag.Name) * ctx.Int(CacheGCFlag.Name) / 100
 	}
-	vmcfg := vm.Config{EnablePreimageRecording: ctx.Bool(VMEnableDebugFlag.Name)}
+	vmcfg := vm.Config{
+		EnablePreimageRecording: ctx.Bool(VMEnableDebugFlag.Name),
+		EnableWitnessCollection: ctx.Bool(CollectWitnessFlag.Name),
+	}
 	if ctx.IsSet(VMTraceFlag.Name) {
 		if name := ctx.String(VMTraceFlag.Name); name != "" {
 			var config json.RawMessage

core/blockchain.go

@@ -1809,7 +1809,7 @@ func (bc *BlockChain) insertChain(chain types.Blocks, setHead bool) (int, error)
 		// while processing transactions. Before Byzantium the prefetcher is mostly
 		// useless due to the intermediate root hashing after each transaction.
 		if bc.chainConfig.IsByzantium(block.Number()) {
-			statedb.StartPrefetcher("chain")
+			statedb.StartPrefetcher("chain", !bc.vmConfig.EnableWitnessCollection)
 		}
 		activeState = statedb
 

core/state/state_object.go

@@ -230,6 +230,14 @@ func (s *stateObject) GetCommittedState(key common.Hash) common.Hash {
 		}
 		value.SetBytes(val)
 	}
+	// Independent of where we loaded the data from, add it to the prefetcher.
+	// Whilst this would be a bit weird if snapshots are disabled, but we still
+	// want the trie nodes to end up in the prefetcher too, so just push through.
+	if s.db.prefetcher != nil && s.data.Root != types.EmptyRootHash {
+		if err = s.db.prefetcher.prefetch(s.addrHash, s.origin.Root, s.address, [][]byte{key[:]}, true); err != nil {
+			log.Error("Failed to prefetch storage slot", "addr", s.address, "key", key, "err", err)
+		}
+	}
 	s.originStorage[key] = value
 	return value
 }
@@ -293,7 +301,7 @@ func (s *stateObject) finalise() {
 		s.pendingStorage[key] = value
 	}
 	if s.db.prefetcher != nil && len(slotsToPrefetch) > 0 && s.data.Root != types.EmptyRootHash {
-		if err := s.db.prefetcher.prefetch(s.addrHash, s.data.Root, s.address, slotsToPrefetch); err != nil {
+		if err := s.db.prefetcher.prefetch(s.addrHash, s.data.Root, s.address, slotsToPrefetch, false); err != nil {
 			log.Error("Failed to prefetch slots", "addr", s.address, "slots", len(slotsToPrefetch), "err", err)
 		}
 	}

core/state/statedb.go

@@ -200,14 +200,14 @@ func (s *StateDB) SetLogger(l *tracing.Hooks) {
 // StartPrefetcher initializes a new trie prefetcher to pull in nodes from the
 // state trie concurrently while the state is mutated so that when we reach the
 // commit phase, most of the needed data is already hot.
-func (s *StateDB) StartPrefetcher(namespace string) {
+func (s *StateDB) StartPrefetcher(namespace string, noreads bool) {
 	if s.prefetcher != nil {
 		s.prefetcher.terminate(false)
 		s.prefetcher.report()
 		s.prefetcher = nil
 	}
 	if s.snap != nil {
-		s.prefetcher = newTriePrefetcher(s.db, s.originalRoot, namespace)
+		s.prefetcher = newTriePrefetcher(s.db, s.originalRoot, namespace, noreads)
 
 		// With the switch to the Proof-of-Stake consensus algorithm, block production
 		// rewards are now handled at the consensus layer. Consequently, a block may
@@ -218,7 +218,7 @@ func (s *StateDB) StartPrefetcher(namespace string) {
 		// To prevent this, the account trie is always scheduled for prefetching once
 		// the prefetcher is constructed. For more details, see:
 		// https://github.com/ethereum/go-ethereum/issues/29880
-		if err := s.prefetcher.prefetch(common.Hash{}, s.originalRoot, common.Address{}, nil); err != nil {
+		if err := s.prefetcher.prefetch(common.Hash{}, s.originalRoot, common.Address{}, nil, false); err != nil {
 			log.Error("Failed to prefetch account trie", "root", s.originalRoot, "err", err)
 		}
 	}
@@ -616,6 +616,14 @@ func (s *StateDB) getStateObject(addr common.Address) *stateObject {
 			return nil
 		}
 	}
+	// Independent of where we loaded the data from, add it to the prefetcher.
+	// Whilst this would be a bit weird if snapshots are disabled, but we still
+	// want the trie nodes to end up in the prefetcher too, so just push through.
+	if s.prefetcher != nil {
+		if err := s.prefetcher.prefetch(common.Hash{}, s.originalRoot, common.Address{}, [][]byte{addr[:]}, true); err != nil {
+			log.Error("Failed to prefetch account", "addr", addr, "err", err)
+		}
+	}
 	// Insert into the live set
 	obj := newObject(s, addr, data)
 	s.setStateObject(obj)
@@ -792,7 +800,7 @@ func (s *StateDB) Finalise(deleteEmptyObjects bool) {
 		addressesToPrefetch = append(addressesToPrefetch, common.CopyBytes(addr[:])) // Copy needed for closure
 	}
 	if s.prefetcher != nil && len(addressesToPrefetch) > 0 {
-		if err := s.prefetcher.prefetch(common.Hash{}, s.originalRoot, common.Address{}, addressesToPrefetch); err != nil {
+		if err := s.prefetcher.prefetch(common.Hash{}, s.originalRoot, common.Address{}, addressesToPrefetch, false); err != nil {
 			log.Error("Failed to prefetch addresses", "addresses", len(addressesToPrefetch), "err", err)
 		}
 	}

core/state/trie_prefetcher.go

@@ -44,31 +44,49 @@ type triePrefetcher struct {
 	root     common.Hash            // Root hash of the account trie for metrics
 	fetchers map[string]*subfetcher // Subfetchers for each trie
 	term     chan struct{}          // Channel to signal interruption
+	noreads  bool                   // Whether to ignore state-read-only prefetch requests
 
 	deliveryMissMeter metrics.Meter
-	accountLoadMeter  metrics.Meter
+
-	accountDupMeter   metrics.Meter
+	accountLoadReadMeter  metrics.Meter
-	accountWasteMeter metrics.Meter
+	accountLoadWriteMeter metrics.Meter
-	storageLoadMeter  metrics.Meter
+	accountDupReadMeter   metrics.Meter
-	storageDupMeter   metrics.Meter
+	accountDupWriteMeter  metrics.Meter
-	storageWasteMeter metrics.Meter
+	accountDupCrossMeter  metrics.Meter
+	accountWasteMeter     metrics.Meter
+
+	storageLoadReadMeter  metrics.Meter
+	storageLoadWriteMeter metrics.Meter
+	storageDupReadMeter   metrics.Meter
+	storageDupWriteMeter  metrics.Meter
+	storageDupCrossMeter  metrics.Meter
+	storageWasteMeter     metrics.Meter
 }
 
-func newTriePrefetcher(db Database, root common.Hash, namespace string) *triePrefetcher {
+func newTriePrefetcher(db Database, root common.Hash, namespace string, noreads bool) *triePrefetcher {
 	prefix := triePrefetchMetricsPrefix + namespace
 	return &triePrefetcher{
 		db:       db,
 		root:     root,
 		fetchers: make(map[string]*subfetcher), // Active prefetchers use the fetchers map
 		term:     make(chan struct{}),
+		noreads:  noreads,
 
 		deliveryMissMeter: metrics.GetOrRegisterMeter(prefix+"/deliverymiss", nil),
-		accountLoadMeter:  metrics.GetOrRegisterMeter(prefix+"/account/load", nil),
+
-		accountDupMeter:   metrics.GetOrRegisterMeter(prefix+"/account/dup", nil),
+		accountLoadReadMeter:  metrics.GetOrRegisterMeter(prefix+"/account/load/read", nil),
-		accountWasteMeter: metrics.GetOrRegisterMeter(prefix+"/account/waste", nil),
+		accountLoadWriteMeter: metrics.GetOrRegisterMeter(prefix+"/account/load/write", nil),
-		storageLoadMeter:  metrics.GetOrRegisterMeter(prefix+"/storage/load", nil),
+		accountDupReadMeter:   metrics.GetOrRegisterMeter(prefix+"/account/dup/read", nil),
-		storageDupMeter:   metrics.GetOrRegisterMeter(prefix+"/storage/dup", nil),
+		accountDupWriteMeter:  metrics.GetOrRegisterMeter(prefix+"/account/dup/write", nil),
-		storageWasteMeter: metrics.GetOrRegisterMeter(prefix+"/storage/waste", nil),
+		accountDupCrossMeter:  metrics.GetOrRegisterMeter(prefix+"/account/dup/cross", nil),
+		accountWasteMeter:     metrics.GetOrRegisterMeter(prefix+"/account/waste", nil),
+
+		storageLoadReadMeter:  metrics.GetOrRegisterMeter(prefix+"/storage/load/read", nil),
+		storageLoadWriteMeter: metrics.GetOrRegisterMeter(prefix+"/storage/load/write", nil),
+		storageDupReadMeter:   metrics.GetOrRegisterMeter(prefix+"/storage/dup/read", nil),
+		storageDupWriteMeter:  metrics.GetOrRegisterMeter(prefix+"/storage/dup/write", nil),
+		storageDupCrossMeter:  metrics.GetOrRegisterMeter(prefix+"/storage/dup/cross", nil),
+		storageWasteMeter:     metrics.GetOrRegisterMeter(prefix+"/storage/waste", nil),
 	}
 }
 
@@ -98,19 +116,31 @@ func (p *triePrefetcher) report() {
 		fetcher.wait() // ensure the fetcher's idle before poking in its internals
 
 		if fetcher.root == p.root {
-			p.accountLoadMeter.Mark(int64(len(fetcher.seen)))
+			p.accountLoadReadMeter.Mark(int64(len(fetcher.seenRead)))
-			p.accountDupMeter.Mark(int64(fetcher.dups))
+			p.accountLoadWriteMeter.Mark(int64(len(fetcher.seenWrite)))
+
+			p.accountDupReadMeter.Mark(int64(fetcher.dupsRead))
+			p.accountDupWriteMeter.Mark(int64(fetcher.dupsWrite))
+			p.accountDupCrossMeter.Mark(int64(fetcher.dupsCross))
+
 			for _, key := range fetcher.used {
-				delete(fetcher.seen, string(key))
+				delete(fetcher.seenRead, string(key))
+				delete(fetcher.seenWrite, string(key))
 			}
-			p.accountWasteMeter.Mark(int64(len(fetcher.seen)))
+			p.accountWasteMeter.Mark(int64(len(fetcher.seenRead) + len(fetcher.seenWrite)))
 		} else {
-			p.storageLoadMeter.Mark(int64(len(fetcher.seen)))
+			p.storageLoadReadMeter.Mark(int64(len(fetcher.seenRead)))
-			p.storageDupMeter.Mark(int64(fetcher.dups))
+			p.storageLoadWriteMeter.Mark(int64(len(fetcher.seenWrite)))
+
+			p.storageDupReadMeter.Mark(int64(fetcher.dupsRead))
+			p.storageDupWriteMeter.Mark(int64(fetcher.dupsWrite))
+			p.storageDupCrossMeter.Mark(int64(fetcher.dupsCross))
+
 			for _, key := range fetcher.used {
-				delete(fetcher.seen, string(key))
+				delete(fetcher.seenRead, string(key))
+				delete(fetcher.seenWrite, string(key))
 			}
-			p.storageWasteMeter.Mark(int64(len(fetcher.seen)))
+			p.storageWasteMeter.Mark(int64(len(fetcher.seenRead) + len(fetcher.seenWrite)))
 		}
 	}
 }
@@ -126,7 +156,11 @@ func (p *triePrefetcher) report() {
 //     upon the same contract, the parameters invoking this method may be
 //     repeated.
 //  2. Finalize of the main account trie. This happens only once per block.
-func (p *triePrefetcher) prefetch(owner common.Hash, root common.Hash, addr common.Address, keys [][]byte) error {
+func (p *triePrefetcher) prefetch(owner common.Hash, root common.Hash, addr common.Address, keys [][]byte, read bool) error {
+	// If the state item is only being read, but reads are disabled, return
+	if read && p.noreads {
+		return nil
+	}
 	// Ensure the subfetcher is still alive
 	select {
 	case <-p.term:
@@ -139,7 +173,7 @@ func (p *triePrefetcher) prefetch(owner common.Hash, root common.Hash, addr comm
 		fetcher = newSubfetcher(p.db, p.root, owner, root, addr)
 		p.fetchers[id] = fetcher
 	}
-	return fetcher.schedule(keys)
+	return fetcher.schedule(keys, read)
 }
 
 // trie returns the trie matching the root hash, blocking until the fetcher of
@@ -186,38 +220,51 @@ type subfetcher struct {
 	addr  common.Address // Address of the account that the trie belongs to
 	trie  Trie           // Trie being populated with nodes
 
-	tasks [][]byte   // Items queued up for retrieval
+	tasks []*subfetcherTask // Items queued up for retrieval
-	lock  sync.Mutex // Lock protecting the task queue
+	lock  sync.Mutex        // Lock protecting the task queue
 
 	wake chan struct{} // Wake channel if a new task is scheduled
 	stop chan struct{} // Channel to interrupt processing
 	term chan struct{} // Channel to signal interruption
 
-	seen map[string]struct{} // Tracks the entries already loaded
+	seenRead  map[string]struct{} // Tracks the entries already loaded via read operations
-	dups int                 // Number of duplicate preload tasks
+	seenWrite map[string]struct{} // Tracks the entries already loaded via write operations
-	used [][]byte            // Tracks the entries used in the end
+
+	dupsRead  int // Number of duplicate preload tasks via reads only
+	dupsWrite int // Number of duplicate preload tasks via writes only
+	dupsCross int // Number of duplicate preload tasks via read-write-crosses
+
+	used [][]byte // Tracks the entries used in the end
+}
+
+// subfetcherTask is a trie path to prefetch, tagged with whether it originates
+// from a read or a write request.
+type subfetcherTask struct {
+	read bool
+	key  []byte
 }
 
 // newSubfetcher creates a goroutine to prefetch state items belonging to a
 // particular root hash.
 func newSubfetcher(db Database, state common.Hash, owner common.Hash, root common.Hash, addr common.Address) *subfetcher {
 	sf := &subfetcher{
-		db:    db,
+		db:        db,
-		state: state,
+		state:     state,
-		owner: owner,
+		owner:     owner,
-		root:  root,
+		root:      root,
-		addr:  addr,
+		addr:      addr,
-		wake:  make(chan struct{}, 1),
+		wake:      make(chan struct{}, 1),
-		stop:  make(chan struct{}),
+		stop:      make(chan struct{}),
-		term:  make(chan struct{}),
+		term:      make(chan struct{}),
-		seen:  make(map[string]struct{}),
+		seenRead:  make(map[string]struct{}),
+		seenWrite: make(map[string]struct{}),
 	}
 	go sf.loop()
 	return sf
 }
 
 // schedule adds a batch of trie keys to the queue to prefetch.
-func (sf *subfetcher) schedule(keys [][]byte) error {
+func (sf *subfetcher) schedule(keys [][]byte, read bool) error {
 	// Ensure the subfetcher is still alive
 	select {
 	case <-sf.term:
@@ -226,7 +273,10 @@ func (sf *subfetcher) schedule(keys [][]byte) error {
 	}
 	// Append the tasks to the current queue
 	sf.lock.Lock()
-	sf.tasks = append(sf.tasks, keys...)
+	for _, key := range keys {
+		key := key // closure for the append below
+		sf.tasks = append(sf.tasks, &subfetcherTask{read: read, key: key})
+	}
 	sf.lock.Unlock()
 
 	// Notify the background thread to execute scheduled tasks
@@ -303,16 +353,36 @@ func (sf *subfetcher) loop() {
 			sf.lock.Unlock()
 
 			for _, task := range tasks {
-				if _, ok := sf.seen[string(task)]; ok {
+				key := string(task.key)
-					sf.dups++
+				if task.read {
-					continue
+					if _, ok := sf.seenRead[key]; ok {
+						sf.dupsRead++
+						continue
+					}
+					if _, ok := sf.seenWrite[key]; ok {
+						sf.dupsCross++
+						continue
+					}
+				} else {
+					if _, ok := sf.seenRead[key]; ok {
+						sf.dupsCross++
+						continue
+					}
+					if _, ok := sf.seenWrite[key]; ok {
+						sf.dupsWrite++
+						continue
+					}
+				}
+				if len(task.key) == common.AddressLength {
+					sf.trie.GetAccount(common.BytesToAddress(task.key))
+				} else {
+					sf.trie.GetStorage(sf.addr, task.key)
 				}
-				if len(task) == common.AddressLength {
+				if task.read {
-					sf.trie.GetAccount(common.BytesToAddress(task))
+					sf.seenRead[key] = struct{}{}
 				} else {
-					sf.trie.GetStorage(sf.addr, task)
+					sf.seenWrite[key] = struct{}{}
 				}
-				sf.seen[string(task)] = struct{}{}
 			}
 
 		case <-sf.stop:

core/state/trie_prefetcher_test.go

@@ -47,15 +47,15 @@ func filledStateDB() *StateDB {
 
 func TestUseAfterTerminate(t *testing.T) {
 	db := filledStateDB()
-	prefetcher := newTriePrefetcher(db.db, db.originalRoot, "")
+	prefetcher := newTriePrefetcher(db.db, db.originalRoot, "", true)
 	skey := common.HexToHash("aaa")
 
-	if err := prefetcher.prefetch(common.Hash{}, db.originalRoot, common.Address{}, [][]byte{skey.Bytes()}); err != nil {
+	if err := prefetcher.prefetch(common.Hash{}, db.originalRoot, common.Address{}, [][]byte{skey.Bytes()}, false); err != nil {
 		t.Errorf("Prefetch failed before terminate: %v", err)
 	}
 	prefetcher.terminate(false)
 
-	if err := prefetcher.prefetch(common.Hash{}, db.originalRoot, common.Address{}, [][]byte{skey.Bytes()}); err == nil {
+	if err := prefetcher.prefetch(common.Hash{}, db.originalRoot, common.Address{}, [][]byte{skey.Bytes()}, false); err == nil {
 		t.Errorf("Prefetch succeeded after terminate: %v", err)
 	}
 	if tr := prefetcher.trie(common.Hash{}, db.originalRoot); tr == nil {

core/vm/interpreter.go

@@ -33,6 +33,7 @@ type Config struct {
 	NoBaseFee               bool  // Forces the EIP-1559 baseFee to 0 (needed for 0 price calls)
 	EnablePreimageRecording bool  // Enables recording of SHA3/keccak preimages
 	ExtraEips               []int // Additional EIPS that are to be enabled
+	EnableWitnessCollection bool  // true if witness collection is enabled
 }
 
 // ScopeContext contains the things that are per-call, such as stack and memory,

eth/backend.go

@@ -184,6 +184,7 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
 	var (
 		vmConfig = vm.Config{
 			EnablePreimageRecording: config.EnablePreimageRecording,
+			EnableWitnessCollection: config.EnableWitnessCollection,
 		}
 		cacheConfig = &core.CacheConfig{
 			TrieCleanLimit:      config.TrieCleanCache,

eth/ethconfig/config.go

@@ -141,6 +141,9 @@ type Config struct {
 	// Enables tracking of SHA3 preimages in the VM
 	EnablePreimageRecording bool
 
+	// Enables prefetching trie nodes for read operations too
+	EnableWitnessCollection bool `toml:"-"`
+
 	// Enables VM tracing
 	VMTrace           string
 	VMTraceJsonConfig string