t.Fatalf("Failed to read stack usage: %v", err)
	}
	if expected, got := 100<<10, stackUsage; got > expected {
		t.Fatalf("expected < %d bytes of memory per thread, got %d", expected, got)
	}
}

func TestSigStackSwapping(t *testing.T) {
	switch runtime.GOOS {
	case "plan9", "windows":
		t.Skipf("no sigaltstack on %s", runtime.GOOS)
	}
	t.Parallel()
	got := runTestProg(t, "testprogcgo", "SigStack")
	want := "OK\n"