diff --git a/core/state/statedb.go b/core/state/statedb.go
index 364a740267..c63cc69458 100644
--- a/core/state/statedb.go
+++ b/core/state/statedb.go
@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"math/big"
 	"runtime"
+	"runtime/debug"
 	"sort"
 	"sync"
 	"time"
@@ -1266,6 +1267,7 @@ var logsPool = sync.Pool{
 }
 
 func (s *StateDB) PutSyncPool() {
+	log.Debug("PutSyncPool", "stack", string(debug.Stack()))
 	for key := range s.parallel.codeReadsInSlot {
 		delete(s.parallel.codeReadsInSlot, key)
 	}