1 files changed, 172 insertions, 0 deletions
diff --git a/src/runtime/stack_test.go b/src/runtime/stack_test.go
index 965c4e6838..485e327c41 100644
--- a/src/runtime/stack_test.go
+++ b/src/runtime/stack_test.go
@@ -453,3 +453,175 @@ func count(n int) int {
 	}
 	return 1 + count(n-1)
 }
+
+func BenchmarkStackCopyNoCache(b *testing.B) {
+	c := make(chan bool)
+	for i := 0; i < b.N; i++ {
+		go func() {
+			count1(1000000)
+			c <- true
+		}()
+		<-c
+	}
+}
+
+func count1(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count2(n-1)
+}
+
+func count2(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count3(n-1)
+}
+
+func count3(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count4(n-1)
+}
+
+func count4(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count5(n-1)
+}
+
+func count5(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count6(n-1)
+}
+
+func count6(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count7(n-1)
+}
+
+func count7(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count8(n-1)
+}
+
+func count8(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count9(n-1)
+}
+
+func count9(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count10(n-1)
+}
+
+func count10(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count11(n-1)
+}
+
+func count11(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count12(n-1)
+}
+
+func count12(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count13(n-1)
+}
+
+func count13(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count14(n-1)
+}
+
+func count14(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count15(n-1)
+}
+
+func count15(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count16(n-1)
+}
+
+func count16(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count17(n-1)
+}
+
+func count17(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count18(n-1)
+}
+
+func count18(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count19(n-1)
+}
+
+func count19(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count20(n-1)
+}
+
+func count20(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count21(n-1)
+}
+
+func count21(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count22(n-1)
+}
+
+func count22(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count23(n-1)
+}
+
+func count23(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return 1 + count1(n-1)
+}