3 files changed, 57 insertions, 0 deletions
diff --git a/src/runtime/export_test.go b/src/runtime/export_test.go
index 831f3f13d4..3c1b4db750 100644
--- a/src/runtime/export_test.go
+++ b/src/runtime/export_test.go
@@ -42,6 +42,8 @@ var PhysHugePageSize = physHugePageSize
 
 var NetpollGenericInit = netpollGenericInit
 
+const PreemptMSupported = preemptMSupported
+
 type LFNode struct {
 	Next    uint64
 	Pushcnt uintptr
diff --git a/src/runtime/proc_test.go b/src/runtime/proc_test.go
index 9b80ce31e5..acee7a1819 100644
--- a/src/runtime/proc_test.go
+++ b/src/runtime/proc_test.go
@@ -356,6 +356,17 @@ func TestPreemptionGC(t *testing.T) {
 	atomic.StoreUint32(&stop, 1)
 }
 
+func TestAsyncPreempt(t *testing.T) {
+	if !runtime.PreemptMSupported {
+		t.Skip("asynchronous preemption not supported on this platform")
+	}
+	output := runTestProg(t, "testprog", "AsyncPreempt")
+	want := "OK\n"
+	if output != want {
+		t.Fatalf("want %s, got %s\n", want, output)
+	}
+}
+
 func TestGCFairness(t *testing.T) {
 	output := runTestProg(t, "testprog", "GCFairness")
 	want := "OK\n"
diff --git a/src/runtime/testdata/testprog/preempt.go b/src/runtime/testdata/testprog/preempt.go
new file mode 100644
index 0000000000..cf004fcb28
--- /dev/null
+++ b/src/runtime/testdata/testprog/preempt.go
@@ -0,0 +1,44 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"runtime"
+	"runtime/debug"
+	"sync/atomic"
+)
+
+func init() {
+	register("AsyncPreempt", AsyncPreempt)
+}
+
+func AsyncPreempt() {
+	// Run with just 1 GOMAXPROCS so the runtime is required to
+	// use scheduler preemption.
+	runtime.GOMAXPROCS(1)
+	// Disable GC so we have complete control of what we're testing.
+	debug.SetGCPercent(-1)
+
+	// Start a goroutine with no sync safe-points.
+	var ready uint32
+	go func() {
+		for {
+			atomic.StoreUint32(&ready, 1)
+		}
+	}()
+
+	// Wait for the goroutine to stop passing through sync
+	// safe-points.
+	for atomic.LoadUint32(&ready) == 0 {
+		runtime.Gosched()
+	}
+
+	// Run a GC, which will have to stop the goroutine for STW and
+	// for stack scanning. If this doesn't work, the test will
+	// deadlock and timeout.
+	runtime.GC()
+
+	println("OK")
+}