runtime: deflake TestPreemptionAfterSyscall

This test occasionally takes very slightly longer than the 3 second
timeout on slow builders (especially windows-386-2008), so increase
the timeout to 5 seconds. It fails with much longer timeouts on Plan
9, so skip it as flaky there.

Updates #41015.

Change-Id: I426a7adfae92c18a0f8a223dd92762b0b91565e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/379214
Trust: Austin Clements <austin@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>

diff --git a/src/runtime/proc_test.go b/src/runtime/proc_test.go
index cc899a24c677acbd83a7cee7a9437f0f58677554..719d0d1aee5a4bf751b5fb0803cee92eaeb8ed9b 100644 (file)
--- a/src/runtime/proc_test.go
+++ b/src/runtime/proc_test.go
@@ -1044,7 +1044,7 @@ func testPreemptionAfterSyscall(t *testing.T, syscallDuration time.Duration) {
                interations = 1
        }
        const (
-               maxDuration = 3 * time.Second
+               maxDuration = 5 * time.Second
                nroutines   = 8
        )
 
@@ -1080,6 +1080,10 @@ func testPreemptionAfterSyscall(t *testing.T, syscallDuration time.Duration) {
 }
 
 func TestPreemptionAfterSyscall(t *testing.T) {
+       if runtime.GOOS == "plan9" {
+               testenv.SkipFlaky(t, 41015)
+       }
+
        for _, i := range []time.Duration{10, 100, 1000} {
                d := i * time.Microsecond
                t.Run(fmt.Sprint(d), func(t *testing.T) {