core/state: parallelise parts of state commit

core/blockchain.go

@@ -1963,7 +1963,7 @@ func (bc *BlockChain) processBlock(block *types.Block, statedb *state.StateDB, s
 	snapshotCommitTimer.Update(statedb.SnapshotCommits) // Snapshot commits are complete, we can mark them
 	triedbCommitTimer.Update(statedb.TrieDBCommits)     // Trie database commits are complete, we can mark them
 
-	blockWriteTimer.Update(time.Since(wstart) - statedb.AccountCommits - statedb.StorageCommits - statedb.SnapshotCommits - statedb.TrieDBCommits)
+	blockWriteTimer.Update(time.Since(wstart) - max(statedb.AccountCommits, statedb.StorageCommits) /* concurrent */ - statedb.SnapshotCommits - statedb.TrieDBCommits)
 	blockInsertTimer.UpdateSince(start)
 
 	return &blockProcessingResult{usedGas: usedGas, procTime: proctime, status: status}, nil

core/state/state_object.go

@@ -403,6 +403,9 @@ func (s *stateObject) updateRoot() {
 // commit obtains a set of dirty storage trie nodes and updates the account data.
 // The returned set can be nil if nothing to commit. This function assumes all
 // storage mutations have already been flushed into trie by updateRoot.
+//
+// Note, commit may run concurrently across all the state objects. Do not assume
+// thread-safe access to the statedb.
 func (s *stateObject) commit() (*trienode.NodeSet, error) {
 	// Short circuit if trie is not even loaded, don't bother with committing anything
 	if s.trie == nil {

core/state/statedb.go

@@ -23,6 +23,7 @@ import (
 	"math/big"
 	"slices"
 	"sort"
+	"sync"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -37,6 +38,7 @@ import (
 	"github.com/ethereum/go-ethereum/trie/trienode"
 	"github.com/ethereum/go-ethereum/trie/triestate"
 	"github.com/holiman/uint256"
+	"golang.org/x/sync/errgroup"
 )
 
 type revision struct {
@@ -1146,66 +1148,108 @@ func (s *StateDB) Commit(block uint64, deleteEmptyObjects bool) (common.Hash, er
 		storageTrieNodesUpdated int
 		storageTrieNodesDeleted int
 		nodes                   = trienode.NewMergedNodeSet()
-		codeWriter              = s.db.DiskDB().NewBatch()
 	)
 	// Handle all state deletions first
 	if err := s.handleDestruction(nodes); err != nil {
 		return common.Hash{}, err
 	}
-	// Handle all state updates afterwards
+	// Handle all state updates afterwards, concurrently to one another to shave
+	// off some milliseconds from the commit operation. Also accumulate the code
+	// writes to run in parallel with the computations.
 	start := time.Now()
+	var (
+		code    = s.db.DiskDB().NewBatch()
+		lock    sync.Mutex
+		root    common.Hash
+		workers errgroup.Group
+	)
+	// Schedule the account trie first since that will be the biggest, so give
+	// it the most time to crunch.
+	//
+	// TODO(karalabe): This account trie commit is *very* heavy. 5-6ms at chain
+	// heads, which seems excessive given that it doesn't do hashing, it just
+	// shuffles some data. For comparison, the *hashing* at chain head is 2-3ms.
+	// We need to investigate what's happening as it seems something's wonky.
+	// Obviously it's not an end of the world issue, just something the original
+	// code didn't anticipate for.
+	workers.Go(func() error {
+		// Write the account trie changes, measuring the amount of wasted time
+		newroot, set, err := s.trie.Commit(true)
+		if err != nil {
+			return err
+		}
+		root = newroot
+
+		// Merge the dirty nodes of account trie into global set
+		lock.Lock()
+		defer lock.Unlock()
+
+		if set != nil {
+			if err = nodes.Merge(set); err != nil {
+				return err
+			}
+			accountTrieNodesUpdated, accountTrieNodesDeleted = set.Size()
+		}
+		s.AccountCommits = time.Since(start)
+		return nil
+	})
+	// Schedule each of the storage tries that need to be updated, so they can
+	// run concurrently to one another.
+	//
+	// TODO(karalabe): Experimentally, the account commit takes approximately the
+	// same time as all the storage commits combined, so we could maybe only have
+	// 2 threads in total. But that kind of depends on the account commit being
+	// more expensive than it should be, so let's fix that and revisit this todo.
 	for addr, op := range s.mutations {
 		if op.isDelete() {
 			continue
 		}
-		obj := s.stateObjects[addr]
-
 		// Write any contract code associated with the state object
+		obj := s.stateObjects[addr]
 		if obj.code != nil && obj.dirtyCode {
-			rawdb.WriteCode(codeWriter, common.BytesToHash(obj.CodeHash()), obj.code)
+			rawdb.WriteCode(code, common.BytesToHash(obj.CodeHash()), obj.code)
 			obj.dirtyCode = false
 		}
-		// Write any storage changes in the state object to its storage trie
-		set, err := obj.commit()
-		if err != nil {
-			return common.Hash{}, err
-		}
-		// Merge the dirty nodes of storage trie into global set. It is possible
-		// that the account was destructed and then resurrected in the same block.
-		// In this case, the node set is shared by both accounts.
-		if set != nil {
-			if err := nodes.Merge(set); err != nil {
-				return common.Hash{}, err
+		// Run the storage updates concurrently to one another
+		workers.Go(func() error {
+			// Write any storage changes in the state object to its storage trie
+			set, err := obj.commit()
+			if err != nil {
+				return err
 			}
-			updates, deleted := set.Size()
-			storageTrieNodesUpdated += updates
-			storageTrieNodesDeleted += deleted
-		}
+			// Merge the dirty nodes of storage trie into global set. It is possible
+			// that the account was destructed and then resurrected in the same block.
+			// In this case, the node set is shared by both accounts.
+			lock.Lock()
+			defer lock.Unlock()
+
+			if set != nil {
+				if err = nodes.Merge(set); err != nil {
+					return err
+				}
+				updates, deleted := set.Size()
+				storageTrieNodesUpdated += updates
+				storageTrieNodesDeleted += deleted
+			}
+			s.StorageCommits = time.Since(start) // overwrite with the longest storage commit runtime
+			return nil
+		})
 	}
-	s.StorageCommits += time.Since(start)
-
-	if codeWriter.ValueSize() > 0 {
-		if err := codeWriter.Write(); err != nil {
-			log.Crit("Failed to commit dirty codes", "error", err)
+	// Schedule the code commits to run concurrently too. This shouldn't really
+	// take much since we don't often commit code, but since it's disk access,
+	// it's always yolo.
+	workers.Go(func() error {
+		if code.ValueSize() > 0 {
+			if err := code.Write(); err != nil {
+				log.Crit("Failed to commit dirty codes", "error", err)
+			}
 		}
-	}
-	// Write the account trie changes, measuring the amount of wasted time
-	start = time.Now()
-
-	root, set, err := s.trie.Commit(true)
-	if err != nil {
+		return nil
+	})
+	// Wait for everything to finish and update the metrics
+	if err := workers.Wait(); err != nil {
 		return common.Hash{}, err
 	}
-	// Merge the dirty nodes of account trie into global set
-	if set != nil {
-		if err := nodes.Merge(set); err != nil {
-			return common.Hash{}, err
-		}
-		accountTrieNodesUpdated, accountTrieNodesDeleted = set.Size()
-	}
-	// Report the commit metrics
-	s.AccountCommits += time.Since(start)
-
 	accountUpdatedMeter.Mark(int64(s.AccountUpdated))
 	storageUpdatedMeter.Mark(int64(s.StorageUpdated))
 	accountDeletedMeter.Mark(int64(s.AccountDeleted))