123 static void io_job_start(struct dm_kcopyd_throttle *t)  in io_job_start()  argument
128 	if (unlikely(!t))  in io_job_start()
134 	throttle = READ_ONCE(t->throttle);  in io_job_start()
140 	difference = now - t->last_jiffies;  in io_job_start()
141 	t->last_jiffies = now;  in io_job_start()
142 	if (t->num_io_jobs)  in io_job_start()
143 		t->io_period += difference;  in io_job_start()
144 	t->total_period += difference;  in io_job_start()
149 	if (unlikely(t->io_period > t->total_period))  in io_job_start()
150 		t->io_period = t->total_period;  in io_job_start()
152 	if (unlikely(t->total_period >= (1 << ACCOUNT_INTERVAL_SHIFT))) {  in io_job_start()
153 		int shift = fls(t->total_period >> ACCOUNT_INTERVAL_SHIFT);  in io_job_start()
155 		t->total_period >>= shift;  in io_job_start()
156 		t->io_period >>= shift;  in io_job_start()
159 	skew = t->io_period - throttle * t->total_period / 100;  in io_job_start()
169 	t->num_io_jobs++;  in io_job_start()
174 static void io_job_finish(struct dm_kcopyd_throttle *t)  in io_job_finish()  argument
178 	if (unlikely(!t))  in io_job_finish()
183 	t->num_io_jobs--;  in io_job_finish()
185 	if (likely(READ_ONCE(t->throttle) >= 100))  in io_job_finish()
188 	if (!t->num_io_jobs) {  in io_job_finish()
192 		difference = now - t->last_jiffies;  in io_job_finish()
193 		t->last_jiffies = now;  in io_job_finish()
195 		t->io_period += difference;  in io_job_finish()
196 		t->total_period += difference;  in io_job_finish()
201 		if (unlikely(t->io_period > t->total_period))  in io_job_finish()
202 			t->io_period = t->total_period;  in io_job_finish()