1 // SPDX-License-Identifier: GPL-2.0-or-later
11  *    based fault-tolerance to ensure that the checkpoint from which a system
14  *    Consider for e.g. Remus - a Virtual Machine checkpointing system,
47  * ------------------+--------------------+---------------->
51  * ----------------->|<--------+--------->|+--------------->
59 	 * a pass-through queue for newly arriving packets.
92 	if (likely(sch->qstats.backlog + skb->len <= q->limit)) {  in plug_enqueue()
93 		if (!q->unplug_indefinite)  in plug_enqueue()
94 			q->pkts_current_epoch++;  in plug_enqueue()
105 	if (q->throttled)  in plug_dequeue()
108 	if (!q->unplug_indefinite) {  in plug_dequeue()
109 		if (!q->pkts_to_release) {  in plug_dequeue()
113 			q->throttled = true;  in plug_dequeue()
116 		q->pkts_to_release--;  in plug_dequeue()
127 	q->pkts_current_epoch = 0;  in plug_init()
128 	q->pkts_last_epoch = 0;  in plug_init()
129 	q->pkts_to_release = 0;  in plug_init()
130 	q->unplug_indefinite = false;  in plug_init()
133 		q->limit = qdisc_dev(sch)->tx_queue_len  in plug_init()
136 		struct tc_plug_qopt *ctl = nla_data(opt);  in plug_init()  local
138 		if (nla_len(opt) < sizeof(*ctl))  in plug_init()
139 			return -EINVAL;  in plug_init()
141 		q->limit = ctl->limit;  in plug_init()
144 	q->throttled = true;  in plug_init()
155  *   command is received (just act as a pass-thru queue).
166 		return -EINVAL;  in plug_change()
168 	switch (msg->action) {  in plug_change()
171 		q->pkts_last_epoch = q->pkts_current_epoch;  in plug_change()
172 		q->pkts_current_epoch = 0;  in plug_change()
173 		if (q->unplug_indefinite)  in plug_change()
174 			q->throttled = true;  in plug_change()
175 		q->unplug_indefinite = false;  in plug_change()
181 		q->pkts_to_release += q->pkts_last_epoch;  in plug_change()
182 		q->pkts_last_epoch = 0;  in plug_change()
183 		q->throttled = false;  in plug_change()
184 		netif_schedule_queue(sch->dev_queue);  in plug_change()
187 		q->unplug_indefinite = true;  in plug_change()
188 		q->pkts_to_release = 0;  in plug_change()
189 		q->pkts_last_epoch = 0;  in plug_change()
190 		q->pkts_current_epoch = 0;  in plug_change()
191 		q->throttled = false;  in plug_change()
192 		netif_schedule_queue(sch->dev_queue);  in plug_change()
196 		q->limit = msg->limit;  in plug_change()
199 		return -EINVAL;  in plug_change()