t.Logf("compare got %v want nil", err)
					ok = false
				}

				return ok
			}

			testCPUProfile(t, acceptProfile, func(dur time.Duration) {
				userTime, systemTime = diffCPUTime(t, func() {
					var wg sync.WaitGroup
					var once sync.Once
					for i := 0; i < tc.workers; i++ {
						wg.Add(1)
						go func() {
							defer wg.Done()
							var salt = 0