diff --git a/src/pkg/runtime/proc_test.go b/src/pkg/runtime/proc_test.go
index 1d51c52..0bbf9fa 100644
--- a/src/pkg/runtime/proc_test.go
+++ b/src/pkg/runtime/proc_test.go
@@ -53,7 +53,7 @@
 	}
 }
 
-func BenchmarkStackGrowth(b *testing.B) {
+func benchmarkStackGrowth(b *testing.B, rec int) {
 	const CallsPerSched = 1000
 	procs := runtime.GOMAXPROCS(-1)
 	N := int32(b.N / CallsPerSched)
@@ -63,7 +63,7 @@
 			for atomic.AddInt32(&N, -1) >= 0 {
 				runtime.Gosched()
 				for g := 0; g < CallsPerSched; g++ {
-					stackGrowthRecursive(10)
+					stackGrowthRecursive(rec)
 				}
 			}
 			c <- true
@@ -74,6 +74,14 @@
 	}
 }
 
+func BenchmarkStackGrowth(b *testing.B) {
+	benchmarkStackGrowth(b, 10)
+}
+
+func BenchmarkStackGrowthDeep(b *testing.B) {
+	benchmarkStackGrowth(b, 1024)
+}
+
 func BenchmarkSyscall(b *testing.B) {
 	const CallsPerSched = 1000
 	procs := runtime.GOMAXPROCS(-1)