37  * Each flow has a CoDel managed queue.
41  * For a given flow, packets are not reordered (CoDel uses a FIFO)
44  * Low memory footprint (64 bytes per flow)
52 	u32		  dropped; /* number of drops (or ECN marks) on this flow */
122 static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow)  in dequeue_head()  argument
124 	struct sk_buff *skb = flow->head;  in dequeue_head()
126 	flow->head = skb->next;  in dequeue_head()
131 /* add skb to flow queue (tail add) */
132 static inline void flow_queue_add(struct fq_codel_flow *flow,  in flow_queue_add()  argument
135 	if (flow->head == NULL)  in flow_queue_add()
136 		flow->head = skb;  in flow_queue_add()
138 		flow->tail->next = skb;  in flow_queue_add()
139 	flow->tail = skb;  in flow_queue_add()
149 	struct fq_codel_flow *flow;  in fq_codel_drop()  local
153 	/* Queue is full! Find the fat flow and drop packet(s) from it.  in fq_codel_drop()
157 	 * In stress mode, we'll try to drop 64 packets from the flow,  in fq_codel_drop()
167 	/* Our goal is to drop half of this fat flow backlog */  in fq_codel_drop()
170 	flow = &q->flows[idx];  in fq_codel_drop()
174 		skb = dequeue_head(flow);  in fq_codel_drop()
180 	flow->dropped += i;  in fq_codel_drop()
194 	struct fq_codel_flow *flow;  in fq_codel_enqueue()  local
209 	flow = &q->flows[idx];  in fq_codel_enqueue()
210 	flow_queue_add(flow, skb);  in fq_codel_enqueue()
214 	if (list_empty(&flow->flowchain)) {  in fq_codel_enqueue()
215 		list_add_tail(&flow->flowchain, &q->new_flows);  in fq_codel_enqueue()
217 		flow->deficit = q->quantum;  in fq_codel_enqueue()
218 		flow->dropped = 0;  in fq_codel_enqueue()
232 	 * in q->backlogs[] to find a fat flow.  in fq_codel_enqueue()
245 	 * If we dropped a packet for this flow, return NET_XMIT_CN,  in fq_codel_enqueue()
265 	struct fq_codel_flow *flow;  in dequeue_func()  local
268 	flow = container_of(vars, struct fq_codel_flow, cvars);  in dequeue_func()
269 	if (flow->head) {  in dequeue_func()
270 		skb = dequeue_head(flow);  in dequeue_func()
271 		q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb);  in dequeue_func()
291 	struct fq_codel_flow *flow;  in fq_codel_dequeue()  local
302 	flow = list_first_entry(head, struct fq_codel_flow, flowchain);  in fq_codel_dequeue()
304 	if (flow->deficit <= 0) {  in fq_codel_dequeue()
305 		flow->deficit += q->quantum;  in fq_codel_dequeue()
306 		list_move_tail(&flow->flowchain, &q->old_flows);  in fq_codel_dequeue()
314 			    &flow->cvars, &q->cstats, qdisc_pkt_len,  in fq_codel_dequeue()
317 	flow->dropped += q->cstats.drop_count - prev_drop_count;  in fq_codel_dequeue()
318 	flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;  in fq_codel_dequeue()
323 			list_move_tail(&flow->flowchain, &q->old_flows);  in fq_codel_dequeue()
325 			list_del_init(&flow->flowchain);  in fq_codel_dequeue()
329 	flow->deficit -= qdisc_pkt_len(skb);  in fq_codel_dequeue()
342 static void fq_codel_flow_purge(struct fq_codel_flow *flow)  in fq_codel_flow_purge()  argument
344 	rtnl_kfree_skbs(flow->head, flow->tail);  in fq_codel_flow_purge()
345 	flow->head = NULL;  in fq_codel_flow_purge()
356 		struct fq_codel_flow *flow = q->flows + i;  in fq_codel_reset()  local
358 		fq_codel_flow_purge(flow);  in fq_codel_reset()
359 		INIT_LIST_HEAD(&flow->flowchain);  in fq_codel_reset()
360 		codel_vars_init(&flow->cvars);  in fq_codel_reset()
505 			struct fq_codel_flow *flow = q->flows + i;  in fq_codel_init()  local
507 			INIT_LIST_HEAD(&flow->flowchain);  in fq_codel_init()
508 			codel_vars_init(&flow->cvars);  in fq_codel_init()
636 		const struct fq_codel_flow *flow = &q->flows[idx];  in fq_codel_dump_class_stats()  local
641 		xstats.class_stats.deficit = flow->deficit;  in fq_codel_dump_class_stats()
643 			codel_time_to_us(flow->cvars.ldelay);  in fq_codel_dump_class_stats()
644 		xstats.class_stats.count = flow->cvars.count;  in fq_codel_dump_class_stats()
645 		xstats.class_stats.lastcount = flow->cvars.lastcount;  in fq_codel_dump_class_stats()
646 		xstats.class_stats.dropping = flow->cvars.dropping;  in fq_codel_dump_class_stats()
647 		if (flow->cvars.dropping) {  in fq_codel_dump_class_stats()
648 			codel_tdiff_t delta = flow->cvars.drop_next -  in fq_codel_dump_class_stats()
655 		if (flow->head) {  in fq_codel_dump_class_stats()
657 			skb = flow->head;  in fq_codel_dump_class_stats()
665 		qs.drops = flow->dropped;  in fq_codel_dump_class_stats()