forked from mirrors/linux
		
	Use bitmap_zalloc()/bitmap_free() instead of hand-writing them. It is less verbose and it improves the semantic. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://lore.kernel.org/r/c7bf099af07eb497b02d195906ee8c11fea3b3bd.1657377335.git.christophe.jaillet@wanadoo.fr Signed-off-by: Jakub Kicinski <kuba@kernel.org>
		
			
				
	
	
		
			389 lines
		
	
	
	
		
			7.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			389 lines
		
	
	
	
		
			7.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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 * Copyright (c) 2016 Qualcomm Atheros, Inc
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 *
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 * Based on net/sched/sch_fq_codel.c
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 */
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#ifndef __NET_SCHED_FQ_IMPL_H
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#define __NET_SCHED_FQ_IMPL_H
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#include <net/fq.h>
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/* functions that are embedded into includer */
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static void
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__fq_adjust_removal(struct fq *fq, struct fq_flow *flow, unsigned int packets,
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		    unsigned int bytes, unsigned int truesize)
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{
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	struct fq_tin *tin = flow->tin;
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	int idx;
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	tin->backlog_bytes -= bytes;
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	tin->backlog_packets -= packets;
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	flow->backlog -= bytes;
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	fq->backlog -= packets;
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	fq->memory_usage -= truesize;
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	if (flow->backlog)
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		return;
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	if (flow == &tin->default_flow) {
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		list_del_init(&tin->tin_list);
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		return;
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	}
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	idx = flow - fq->flows;
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	__clear_bit(idx, fq->flows_bitmap);
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}
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static void fq_adjust_removal(struct fq *fq,
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			      struct fq_flow *flow,
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			      struct sk_buff *skb)
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{
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	__fq_adjust_removal(fq, flow, 1, skb->len, skb->truesize);
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}
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static struct sk_buff *fq_flow_dequeue(struct fq *fq,
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				       struct fq_flow *flow)
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{
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	struct sk_buff *skb;
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	lockdep_assert_held(&fq->lock);
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	skb = __skb_dequeue(&flow->queue);
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	if (!skb)
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		return NULL;
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	fq_adjust_removal(fq, flow, skb);
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	return skb;
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}
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static int fq_flow_drop(struct fq *fq, struct fq_flow *flow,
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			fq_skb_free_t free_func)
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{
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	unsigned int packets = 0, bytes = 0, truesize = 0;
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	struct fq_tin *tin = flow->tin;
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	struct sk_buff *skb;
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	int pending;
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	lockdep_assert_held(&fq->lock);
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	pending = min_t(int, 32, skb_queue_len(&flow->queue) / 2);
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	do {
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		skb = __skb_dequeue(&flow->queue);
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		if (!skb)
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			break;
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		packets++;
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		bytes += skb->len;
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		truesize += skb->truesize;
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		free_func(fq, tin, flow, skb);
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	} while (packets < pending);
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	__fq_adjust_removal(fq, flow, packets, bytes, truesize);
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	return packets;
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}
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static struct sk_buff *fq_tin_dequeue(struct fq *fq,
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				      struct fq_tin *tin,
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				      fq_tin_dequeue_t dequeue_func)
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{
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	struct fq_flow *flow;
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	struct list_head *head;
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	struct sk_buff *skb;
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	lockdep_assert_held(&fq->lock);
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begin:
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	head = &tin->new_flows;
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	if (list_empty(head)) {
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		head = &tin->old_flows;
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		if (list_empty(head))
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			return NULL;
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	}
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	flow = list_first_entry(head, struct fq_flow, flowchain);
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	if (flow->deficit <= 0) {
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		flow->deficit += fq->quantum;
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		list_move_tail(&flow->flowchain,
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			       &tin->old_flows);
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		goto begin;
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	}
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	skb = dequeue_func(fq, tin, flow);
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	if (!skb) {
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		/* force a pass through old_flows to prevent starvation */
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		if ((head == &tin->new_flows) &&
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		    !list_empty(&tin->old_flows)) {
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			list_move_tail(&flow->flowchain, &tin->old_flows);
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		} else {
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			list_del_init(&flow->flowchain);
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			flow->tin = NULL;
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		}
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		goto begin;
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	}
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	flow->deficit -= skb->len;
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	tin->tx_bytes += skb->len;
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	tin->tx_packets++;
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	return skb;
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}
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static u32 fq_flow_idx(struct fq *fq, struct sk_buff *skb)
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{
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	u32 hash = skb_get_hash(skb);
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	return reciprocal_scale(hash, fq->flows_cnt);
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}
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static struct fq_flow *fq_flow_classify(struct fq *fq,
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					struct fq_tin *tin, u32 idx,
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					struct sk_buff *skb)
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{
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	struct fq_flow *flow;
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	lockdep_assert_held(&fq->lock);
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	flow = &fq->flows[idx];
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	if (flow->tin && flow->tin != tin) {
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		flow = &tin->default_flow;
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		tin->collisions++;
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		fq->collisions++;
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	}
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	if (!flow->tin)
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		tin->flows++;
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	return flow;
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}
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static struct fq_flow *fq_find_fattest_flow(struct fq *fq)
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{
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	struct fq_tin *tin;
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	struct fq_flow *flow = NULL;
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	u32 len = 0;
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	int i;
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	for_each_set_bit(i, fq->flows_bitmap, fq->flows_cnt) {
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		struct fq_flow *cur = &fq->flows[i];
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		unsigned int cur_len;
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		cur_len = cur->backlog;
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		if (cur_len <= len)
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			continue;
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		flow = cur;
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		len = cur_len;
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	}
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	list_for_each_entry(tin, &fq->tin_backlog, tin_list) {
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		unsigned int cur_len = tin->default_flow.backlog;
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		if (cur_len <= len)
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			continue;
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		flow = &tin->default_flow;
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		len = cur_len;
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	}
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	return flow;
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}
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static void fq_tin_enqueue(struct fq *fq,
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			   struct fq_tin *tin, u32 idx,
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			   struct sk_buff *skb,
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			   fq_skb_free_t free_func)
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{
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	struct fq_flow *flow;
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	bool oom;
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	lockdep_assert_held(&fq->lock);
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	flow = fq_flow_classify(fq, tin, idx, skb);
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	if (!flow->backlog) {
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		if (flow != &tin->default_flow)
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			__set_bit(idx, fq->flows_bitmap);
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		else if (list_empty(&tin->tin_list))
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			list_add(&tin->tin_list, &fq->tin_backlog);
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	}
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	flow->tin = tin;
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	flow->backlog += skb->len;
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	tin->backlog_bytes += skb->len;
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	tin->backlog_packets++;
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	fq->memory_usage += skb->truesize;
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	fq->backlog++;
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	if (list_empty(&flow->flowchain)) {
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		flow->deficit = fq->quantum;
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		list_add_tail(&flow->flowchain,
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			      &tin->new_flows);
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	}
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	__skb_queue_tail(&flow->queue, skb);
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	oom = (fq->memory_usage > fq->memory_limit);
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	while (fq->backlog > fq->limit || oom) {
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		flow = fq_find_fattest_flow(fq);
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		if (!flow)
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			return;
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		if (!fq_flow_drop(fq, flow, free_func))
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			return;
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		flow->tin->overlimit++;
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		fq->overlimit++;
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		if (oom) {
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			fq->overmemory++;
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			oom = (fq->memory_usage > fq->memory_limit);
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		}
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	}
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}
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static void fq_flow_filter(struct fq *fq,
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			   struct fq_flow *flow,
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			   fq_skb_filter_t filter_func,
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			   void *filter_data,
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			   fq_skb_free_t free_func)
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{
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	struct fq_tin *tin = flow->tin;
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	struct sk_buff *skb, *tmp;
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	lockdep_assert_held(&fq->lock);
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	skb_queue_walk_safe(&flow->queue, skb, tmp) {
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		if (!filter_func(fq, tin, flow, skb, filter_data))
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			continue;
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		__skb_unlink(skb, &flow->queue);
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		fq_adjust_removal(fq, flow, skb);
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		free_func(fq, tin, flow, skb);
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	}
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}
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static void fq_tin_filter(struct fq *fq,
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			  struct fq_tin *tin,
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			  fq_skb_filter_t filter_func,
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			  void *filter_data,
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			  fq_skb_free_t free_func)
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{
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	struct fq_flow *flow;
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	lockdep_assert_held(&fq->lock);
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	list_for_each_entry(flow, &tin->new_flows, flowchain)
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		fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
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	list_for_each_entry(flow, &tin->old_flows, flowchain)
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		fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
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}
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static void fq_flow_reset(struct fq *fq,
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			  struct fq_flow *flow,
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			  fq_skb_free_t free_func)
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{
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	struct fq_tin *tin = flow->tin;
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	struct sk_buff *skb;
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	while ((skb = fq_flow_dequeue(fq, flow)))
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		free_func(fq, tin, flow, skb);
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	if (!list_empty(&flow->flowchain)) {
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		list_del_init(&flow->flowchain);
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		if (list_empty(&tin->new_flows) &&
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		    list_empty(&tin->old_flows))
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			list_del_init(&tin->tin_list);
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	}
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	flow->tin = NULL;
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	WARN_ON_ONCE(flow->backlog);
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}
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static void fq_tin_reset(struct fq *fq,
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			 struct fq_tin *tin,
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			 fq_skb_free_t free_func)
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{
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	struct list_head *head;
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	struct fq_flow *flow;
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	for (;;) {
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		head = &tin->new_flows;
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		if (list_empty(head)) {
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			head = &tin->old_flows;
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			if (list_empty(head))
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				break;
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		}
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		flow = list_first_entry(head, struct fq_flow, flowchain);
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		fq_flow_reset(fq, flow, free_func);
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	}
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	WARN_ON_ONCE(!list_empty(&tin->tin_list));
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	WARN_ON_ONCE(tin->backlog_bytes);
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	WARN_ON_ONCE(tin->backlog_packets);
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}
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static void fq_flow_init(struct fq_flow *flow)
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{
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	INIT_LIST_HEAD(&flow->flowchain);
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	__skb_queue_head_init(&flow->queue);
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}
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static void fq_tin_init(struct fq_tin *tin)
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{
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	INIT_LIST_HEAD(&tin->new_flows);
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	INIT_LIST_HEAD(&tin->old_flows);
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	INIT_LIST_HEAD(&tin->tin_list);
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	fq_flow_init(&tin->default_flow);
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}
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static int fq_init(struct fq *fq, int flows_cnt)
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{
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	int i;
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	memset(fq, 0, sizeof(fq[0]));
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	spin_lock_init(&fq->lock);
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	INIT_LIST_HEAD(&fq->tin_backlog);
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	fq->flows_cnt = max_t(u32, flows_cnt, 1);
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	fq->quantum = 300;
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	fq->limit = 8192;
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	fq->memory_limit = 16 << 20; /* 16 MBytes */
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	fq->flows = kvcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
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	if (!fq->flows)
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		return -ENOMEM;
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	fq->flows_bitmap = bitmap_zalloc(fq->flows_cnt, GFP_KERNEL);
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	if (!fq->flows_bitmap) {
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		kvfree(fq->flows);
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		fq->flows = NULL;
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		return -ENOMEM;
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	}
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	for (i = 0; i < fq->flows_cnt; i++)
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		fq_flow_init(&fq->flows[i]);
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	return 0;
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}
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static void fq_reset(struct fq *fq,
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		     fq_skb_free_t free_func)
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{
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	int i;
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	for (i = 0; i < fq->flows_cnt; i++)
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		fq_flow_reset(fq, &fq->flows[i], free_func);
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	kvfree(fq->flows);
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	fq->flows = NULL;
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	bitmap_free(fq->flows_bitmap);
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	fq->flows_bitmap = NULL;
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}
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#endif
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