runtime: try harder to get different iteration orders.

Fixes #8736.

LGTM=iant, josharian
R=golang-codereviews, iant, josharian
CC=golang-codereviews
https://golang.org/cl/144910044

diff --git a/src/runtime/map_test.go b/src/runtime/map_test.go
index 9b76a5bbf27d5f09b1eef4a6903b3feac70a1d96..92da2d8209b2a4b18a399f7774dc2f1988750d5d 100644 (file)
--- a/src/runtime/map_test.go
+++ b/src/runtime/map_test.go
@@ -462,8 +462,9 @@ NextRound:
                        first = append(first, i)
                }
 
-               // 80 chances to get a different iteration order.
-               for n := 0; n < 80; n++ {
+               // 800 chances to get a different iteration order.
+               // See bug 8736 for why we need so many tries.
+               for n := 0; n < 800; n++ {
                        idx := 0
                        for i := range m {
                                if i != first[idx] {