core/state: fix prefetch on single core CPU (ethereum#32075)

cskiraly · howjmay · commit cb17078fa2e9 · 2025-08-28T01:23:11.000+08:00
We need at least one prefetch goroutine. SetLimit(0) would block
prefetch.

Signed-off-by: Csaba Kiraly &lt;csaba.kiraly@gmail.com&gt;
diff --git a/core/state_prefetcher.go b/core/state_prefetcher.go
@@ -57,7 +57,7 @@ func (p *statePrefetcher) Prefetch(block *types.Block, statedb *state.StateDB, c
 		workers errgroup.Group
 		reader  = statedb.Reader()
 	)
-	workers.SetLimit(4 * runtime.NumCPU() / 5) // Aggressively run the prefetching
+	workers.SetLimit(max(1, 4*runtime.NumCPU()/5)) // Aggressively run the prefetching
 
 	// Iterate over and process the individual transactions
 	for i, tx := range block.Transactions() {

Original file line number	Diff line number	Diff line change
`@@ -57,7 +57,7 @@ func (p statePrefetcher) Prefetch(block types.Block, statedb *state.StateDB, c`
`57`	`57`	`workers errgroup.Group`
`58`	`58`	`reader = statedb.Reader()`
`59`	`59`	`)`
`60`		`- workers.SetLimit(4 * runtime.NumCPU() / 5) // Aggressively run the prefetching`
	`60`	`+ workers.SetLimit(max(1, 4*runtime.NumCPU()/5)) // Aggressively run the prefetching`
`61`	`61`
`62`	`62`	`// Iterate over and process the individual transactions`
`63`	`63`	`for i, tx := range block.Transactions() {`