func BenchmarkMutexNoSpin(b *testing.B) {
	b.ResetTimer()
	b.ReportAllocs()

	// This benchmark models a situation where spinning in the mutex should be
	// non-profitable and allows to confirm that spinning does not do harm.
	// To achieve this we create excess of goroutines most of which do local work.
	// These goroutines yield during local work, so that switching from
	// a blocked goroutine to other goroutines is profitable.