Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Mohit P. Tahiliani | 2722 | 93.57% | 1 | 7.69% |
Eric Dumazet | 120 | 4.13% | 4 | 30.77% |
Davide Caratti | 26 | 0.89% | 3 | 23.08% |
Vijay Subramanian | 26 | 0.89% | 1 | 7.69% |
Dan Carpenter | 7 | 0.24% | 1 | 7.69% |
Gautam Ramakrishnan | 5 | 0.17% | 1 | 7.69% |
Gustavo A. R. Silva | 2 | 0.07% | 1 | 7.69% |
Jakub Kiciński | 1 | 0.03% | 1 | 7.69% |
Total | 2909 | 13 |
// SPDX-License-Identifier: GPL-2.0-only /* Flow Queue PIE discipline * * Copyright (C) 2019 Mohit P. Tahiliani <tahiliani@nitk.edu.in> * Copyright (C) 2019 Sachin D. Patil <sdp.sachin@gmail.com> * Copyright (C) 2019 V. Saicharan <vsaicharan1998@gmail.com> * Copyright (C) 2019 Mohit Bhasi <mohitbhasi1998@gmail.com> * Copyright (C) 2019 Leslie Monis <lesliemonis@gmail.com> * Copyright (C) 2019 Gautam Ramakrishnan <gautamramk@gmail.com> */ #include <linux/jhash.h> #include <linux/sizes.h> #include <linux/vmalloc.h> #include <net/pkt_cls.h> #include <net/pie.h> /* Flow Queue PIE * * Principles: * - Packets are classified on flows. * - This is a Stochastic model (as we use a hash, several flows might * be hashed to the same slot) * - Each flow has a PIE managed queue. * - Flows are linked onto two (Round Robin) lists, * so that new flows have priority on old ones. * - For a given flow, packets are not reordered. * - Drops during enqueue only. * - ECN capability is off by default. * - ECN threshold (if ECN is enabled) is at 10% by default. * - Uses timestamps to calculate queue delay by default. */ /** * struct fq_pie_flow - contains data for each flow * @vars: pie vars associated with the flow * @deficit: number of remaining byte credits * @backlog: size of data in the flow * @qlen: number of packets in the flow * @flowchain: flowchain for the flow * @head: first packet in the flow * @tail: last packet in the flow */ struct fq_pie_flow { struct pie_vars vars; s32 deficit; u32 backlog; u32 qlen; struct list_head flowchain; struct sk_buff *head; struct sk_buff *tail; }; struct fq_pie_sched_data { struct tcf_proto __rcu *filter_list; /* optional external classifier */ struct tcf_block *block; struct fq_pie_flow *flows; struct Qdisc *sch; struct list_head old_flows; struct list_head new_flows; struct pie_params p_params; u32 ecn_prob; u32 flows_cnt; u32 flows_cursor; u32 quantum; u32 memory_limit; u32 new_flow_count; u32 memory_usage; u32 overmemory; struct pie_stats stats; struct timer_list adapt_timer; }; static unsigned int fq_pie_hash(const struct fq_pie_sched_data *q, struct sk_buff *skb) { return reciprocal_scale(skb_get_hash(skb), q->flows_cnt); } static unsigned int fq_pie_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) { struct fq_pie_sched_data *q = qdisc_priv(sch); struct tcf_proto *filter; struct tcf_result res; int result; if (TC_H_MAJ(skb->priority) == sch->handle && TC_H_MIN(skb->priority) > 0 && TC_H_MIN(skb->priority) <= q->flows_cnt) return TC_H_MIN(skb->priority); filter = rcu_dereference_bh(q->filter_list); if (!filter) return fq_pie_hash(q, skb) + 1; *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; result = tcf_classify(skb, NULL, filter, &res, false); if (result >= 0) { #ifdef CONFIG_NET_CLS_ACT switch (result) { case TC_ACT_STOLEN: case TC_ACT_QUEUED: case TC_ACT_TRAP: *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; fallthrough; case TC_ACT_SHOT: return 0; } #endif if (TC_H_MIN(res.classid) <= q->flows_cnt) return TC_H_MIN(res.classid); } return 0; } /* add skb to flow queue (tail add) */ static inline void flow_queue_add(struct fq_pie_flow *flow, struct sk_buff *skb) { if (!flow->head) flow->head = skb; else flow->tail->next = skb; flow->tail = skb; skb->next = NULL; } static int fq_pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { struct fq_pie_sched_data *q = qdisc_priv(sch); struct fq_pie_flow *sel_flow; int ret; u8 memory_limited = false; u8 enqueue = false; u32 pkt_len; u32 idx; /* Classifies packet into corresponding flow */ idx = fq_pie_classify(skb, sch, &ret); if (idx == 0) { if (ret & __NET_XMIT_BYPASS) qdisc_qstats_drop(sch); __qdisc_drop(skb, to_free); return ret; } idx--; sel_flow = &q->flows[idx]; /* Checks whether adding a new packet would exceed memory limit */ get_pie_cb(skb)->mem_usage = skb->truesize; memory_limited = q->memory_usage > q->memory_limit + skb->truesize; /* Checks if the qdisc is full */ if (unlikely(qdisc_qlen(sch) >= sch->limit)) { q->stats.overlimit++; goto out; } else if (unlikely(memory_limited)) { q->overmemory++; } if (!pie_drop_early(sch, &q->p_params, &sel_flow->vars, sel_flow->backlog, skb->len)) { enqueue = true; } else if (q->p_params.ecn && sel_flow->vars.prob <= (MAX_PROB / 100) * q->ecn_prob && INET_ECN_set_ce(skb)) { /* If packet is ecn capable, mark it if drop probability * is lower than the parameter ecn_prob, else drop it. */ q->stats.ecn_mark++; enqueue = true; } if (enqueue) { /* Set enqueue time only when dq_rate_estimator is disabled. */ if (!q->p_params.dq_rate_estimator) pie_set_enqueue_time(skb); pkt_len = qdisc_pkt_len(skb); q->stats.packets_in++; q->memory_usage += skb->truesize; sch->qstats.backlog += pkt_len; sch->q.qlen++; flow_queue_add(sel_flow, skb); if (list_empty(&sel_flow->flowchain)) { list_add_tail(&sel_flow->flowchain, &q->new_flows); q->new_flow_count++; sel_flow->deficit = q->quantum; sel_flow->qlen = 0; sel_flow->backlog = 0; } sel_flow->qlen++; sel_flow->backlog += pkt_len; return NET_XMIT_SUCCESS; } out: q->stats.dropped++; sel_flow->vars.accu_prob = 0; __qdisc_drop(skb, to_free); qdisc_qstats_drop(sch); return NET_XMIT_CN; } static const struct netlink_range_validation fq_pie_q_range = { .min = 1, .max = 1 << 20, }; static const struct nla_policy fq_pie_policy[TCA_FQ_PIE_MAX + 1] = { [TCA_FQ_PIE_LIMIT] = {.type = NLA_U32}, [TCA_FQ_PIE_FLOWS] = {.type = NLA_U32}, [TCA_FQ_PIE_TARGET] = {.type = NLA_U32}, [TCA_FQ_PIE_TUPDATE] = {.type = NLA_U32}, [TCA_FQ_PIE_ALPHA] = {.type = NLA_U32}, [TCA_FQ_PIE_BETA] = {.type = NLA_U32}, [TCA_FQ_PIE_QUANTUM] = NLA_POLICY_FULL_RANGE(NLA_U32, &fq_pie_q_range), [TCA_FQ_PIE_MEMORY_LIMIT] = {.type = NLA_U32}, [TCA_FQ_PIE_ECN_PROB] = {.type = NLA_U32}, [TCA_FQ_PIE_ECN] = {.type = NLA_U32}, [TCA_FQ_PIE_BYTEMODE] = {.type = NLA_U32}, [TCA_FQ_PIE_DQ_RATE_ESTIMATOR] = {.type = NLA_U32}, }; static inline struct sk_buff *dequeue_head(struct fq_pie_flow *flow) { struct sk_buff *skb = flow->head; flow->head = skb->next; skb->next = NULL; return skb; } static struct sk_buff *fq_pie_qdisc_dequeue(struct Qdisc *sch) { struct fq_pie_sched_data *q = qdisc_priv(sch); struct sk_buff *skb = NULL; struct fq_pie_flow *flow; struct list_head *head; u32 pkt_len; begin: head = &q->new_flows; if (list_empty(head)) { head = &q->old_flows; if (list_empty(head)) return NULL; } flow = list_first_entry(head, struct fq_pie_flow, flowchain); /* Flow has exhausted all its credits */ if (flow->deficit <= 0) { flow->deficit += q->quantum; list_move_tail(&flow->flowchain, &q->old_flows); goto begin; } if (flow->head) { skb = dequeue_head(flow); pkt_len = qdisc_pkt_len(skb); sch->qstats.backlog -= pkt_len; sch->q.qlen--; qdisc_bstats_update(sch, skb); } if (!skb) { /* force a pass through old_flows to prevent starvation */ if (head == &q->new_flows && !list_empty(&q->old_flows)) list_move_tail(&flow->flowchain, &q->old_flows); else list_del_init(&flow->flowchain); goto begin; } flow->qlen--; flow->deficit -= pkt_len; flow->backlog -= pkt_len; q->memory_usage -= get_pie_cb(skb)->mem_usage; pie_process_dequeue(skb, &q->p_params, &flow->vars, flow->backlog); return skb; } static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack) { struct fq_pie_sched_data *q = qdisc_priv(sch); struct nlattr *tb[TCA_FQ_PIE_MAX + 1]; unsigned int len_dropped = 0; unsigned int num_dropped = 0; int err; err = nla_parse_nested(tb, TCA_FQ_PIE_MAX, opt, fq_pie_policy, extack); if (err < 0) return err; sch_tree_lock(sch); if (tb[TCA_FQ_PIE_LIMIT]) { u32 limit = nla_get_u32(tb[TCA_FQ_PIE_LIMIT]); q->p_params.limit = limit; sch->limit = limit; } if (tb[TCA_FQ_PIE_FLOWS]) { if (q->flows) { NL_SET_ERR_MSG_MOD(extack, "Number of flows cannot be changed"); goto flow_error; } q->flows_cnt = nla_get_u32(tb[TCA_FQ_PIE_FLOWS]); if (!q->flows_cnt || q->flows_cnt > 65536) { NL_SET_ERR_MSG_MOD(extack, "Number of flows must range in [1..65536]"); goto flow_error; } } /* convert from microseconds to pschedtime */ if (tb[TCA_FQ_PIE_TARGET]) { /* target is in us */ u32 target = nla_get_u32(tb[TCA_FQ_PIE_TARGET]); /* convert to pschedtime */ q->p_params.target = PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC); } /* tupdate is in jiffies */ if (tb[TCA_FQ_PIE_TUPDATE]) q->p_params.tupdate = usecs_to_jiffies(nla_get_u32(tb[TCA_FQ_PIE_TUPDATE])); if (tb[TCA_FQ_PIE_ALPHA]) q->p_params.alpha = nla_get_u32(tb[TCA_FQ_PIE_ALPHA]); if (tb[TCA_FQ_PIE_BETA]) q->p_params.beta = nla_get_u32(tb[TCA_FQ_PIE_BETA]); if (tb[TCA_FQ_PIE_QUANTUM]) q->quantum = nla_get_u32(tb[TCA_FQ_PIE_QUANTUM]); if (tb[TCA_FQ_PIE_MEMORY_LIMIT]) q->memory_limit = nla_get_u32(tb[TCA_FQ_PIE_MEMORY_LIMIT]); if (tb[TCA_FQ_PIE_ECN_PROB]) q->ecn_prob = nla_get_u32(tb[TCA_FQ_PIE_ECN_PROB]); if (tb[TCA_FQ_PIE_ECN]) q->p_params.ecn = nla_get_u32(tb[TCA_FQ_PIE_ECN]); if (tb[TCA_FQ_PIE_BYTEMODE]) q->p_params.bytemode = nla_get_u32(tb[TCA_FQ_PIE_BYTEMODE]); if (tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR]) q->p_params.dq_rate_estimator = nla_get_u32(tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR]); /* Drop excess packets if new limit is lower */ while (sch->q.qlen > sch->limit) { struct sk_buff *skb = fq_pie_qdisc_dequeue(sch); len_dropped += qdisc_pkt_len(skb); num_dropped += 1; rtnl_kfree_skbs(skb, skb); } qdisc_tree_reduce_backlog(sch, num_dropped, len_dropped); sch_tree_unlock(sch); return 0; flow_error: sch_tree_unlock(sch); return -EINVAL; } static void fq_pie_timer(struct timer_list *t) { struct fq_pie_sched_data *q = from_timer(q, t, adapt_timer); unsigned long next, tupdate; struct Qdisc *sch = q->sch; spinlock_t *root_lock; /* to lock qdisc for probability calculations */ int max_cnt, i; rcu_read_lock(); root_lock = qdisc_lock(qdisc_root_sleeping(sch)); spin_lock(root_lock); /* Limit this expensive loop to 2048 flows per round. */ max_cnt = min_t(int, q->flows_cnt - q->flows_cursor, 2048); for (i = 0; i < max_cnt; i++) { pie_calculate_probability(&q->p_params, &q->flows[q->flows_cursor].vars, q->flows[q->flows_cursor].backlog); q->flows_cursor++; } tupdate = q->p_params.tupdate; next = 0; if (q->flows_cursor >= q->flows_cnt) { q->flows_cursor = 0; next = tupdate; } if (tupdate) mod_timer(&q->adapt_timer, jiffies + next); spin_unlock(root_lock); rcu_read_unlock(); } static int fq_pie_init(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack) { struct fq_pie_sched_data *q = qdisc_priv(sch); int err; u32 idx; pie_params_init(&q->p_params); sch->limit = 10 * 1024; q->p_params.limit = sch->limit; q->quantum = psched_mtu(qdisc_dev(sch)); q->sch = sch; q->ecn_prob = 10; q->flows_cnt = 1024; q->memory_limit = SZ_32M; INIT_LIST_HEAD(&q->new_flows); INIT_LIST_HEAD(&q->old_flows); timer_setup(&q->adapt_timer, fq_pie_timer, 0); if (opt) { err = fq_pie_change(sch, opt, extack); if (err) return err; } err = tcf_block_get(&q->block, &q->filter_list, sch, extack); if (err) goto init_failure; q->flows = kvcalloc(q->flows_cnt, sizeof(struct fq_pie_flow), GFP_KERNEL); if (!q->flows) { err = -ENOMEM; goto init_failure; } for (idx = 0; idx < q->flows_cnt; idx++) { struct fq_pie_flow *flow = q->flows + idx; INIT_LIST_HEAD(&flow->flowchain); pie_vars_init(&flow->vars); } mod_timer(&q->adapt_timer, jiffies + HZ / 2); return 0; init_failure: q->flows_cnt = 0; return err; } static int fq_pie_dump(struct Qdisc *sch, struct sk_buff *skb) { struct fq_pie_sched_data *q = qdisc_priv(sch); struct nlattr *opts; opts = nla_nest_start(skb, TCA_OPTIONS); if (!opts) return -EMSGSIZE; /* convert target from pschedtime to us */ if (nla_put_u32(skb, TCA_FQ_PIE_LIMIT, sch->limit) || nla_put_u32(skb, TCA_FQ_PIE_FLOWS, q->flows_cnt) || nla_put_u32(skb, TCA_FQ_PIE_TARGET, ((u32)PSCHED_TICKS2NS(q->p_params.target)) / NSEC_PER_USEC) || nla_put_u32(skb, TCA_FQ_PIE_TUPDATE, jiffies_to_usecs(q->p_params.tupdate)) || nla_put_u32(skb, TCA_FQ_PIE_ALPHA, q->p_params.alpha) || nla_put_u32(skb, TCA_FQ_PIE_BETA, q->p_params.beta) || nla_put_u32(skb, TCA_FQ_PIE_QUANTUM, q->quantum) || nla_put_u32(skb, TCA_FQ_PIE_MEMORY_LIMIT, q->memory_limit) || nla_put_u32(skb, TCA_FQ_PIE_ECN_PROB, q->ecn_prob) || nla_put_u32(skb, TCA_FQ_PIE_ECN, q->p_params.ecn) || nla_put_u32(skb, TCA_FQ_PIE_BYTEMODE, q->p_params.bytemode) || nla_put_u32(skb, TCA_FQ_PIE_DQ_RATE_ESTIMATOR, q->p_params.dq_rate_estimator)) goto nla_put_failure; return nla_nest_end(skb, opts); nla_put_failure: nla_nest_cancel(skb, opts); return -EMSGSIZE; } static int fq_pie_dump_stats(struct Qdisc *sch, struct gnet_dump *d) { struct fq_pie_sched_data *q = qdisc_priv(sch); struct tc_fq_pie_xstats st = { .packets_in = q->stats.packets_in, .overlimit = q->stats.overlimit, .overmemory = q->overmemory, .dropped = q->stats.dropped, .ecn_mark = q->stats.ecn_mark, .new_flow_count = q->new_flow_count, .memory_usage = q->memory_usage, }; struct list_head *pos; sch_tree_lock(sch); list_for_each(pos, &q->new_flows) st.new_flows_len++; list_for_each(pos, &q->old_flows) st.old_flows_len++; sch_tree_unlock(sch); return gnet_stats_copy_app(d, &st, sizeof(st)); } static void fq_pie_reset(struct Qdisc *sch) { struct fq_pie_sched_data *q = qdisc_priv(sch); u32 idx; INIT_LIST_HEAD(&q->new_flows); INIT_LIST_HEAD(&q->old_flows); for (idx = 0; idx < q->flows_cnt; idx++) { struct fq_pie_flow *flow = q->flows + idx; /* Removes all packets from flow */ rtnl_kfree_skbs(flow->head, flow->tail); flow->head = NULL; INIT_LIST_HEAD(&flow->flowchain); pie_vars_init(&flow->vars); } } static void fq_pie_destroy(struct Qdisc *sch) { struct fq_pie_sched_data *q = qdisc_priv(sch); tcf_block_put(q->block); q->p_params.tupdate = 0; del_timer_sync(&q->adapt_timer); kvfree(q->flows); } static struct Qdisc_ops fq_pie_qdisc_ops __read_mostly = { .id = "fq_pie", .priv_size = sizeof(struct fq_pie_sched_data), .enqueue = fq_pie_qdisc_enqueue, .dequeue = fq_pie_qdisc_dequeue, .peek = qdisc_peek_dequeued, .init = fq_pie_init, .destroy = fq_pie_destroy, .reset = fq_pie_reset, .change = fq_pie_change, .dump = fq_pie_dump, .dump_stats = fq_pie_dump_stats, .owner = THIS_MODULE, }; static int __init fq_pie_module_init(void) { return register_qdisc(&fq_pie_qdisc_ops); } static void __exit fq_pie_module_exit(void) { unregister_qdisc(&fq_pie_qdisc_ops); } module_init(fq_pie_module_init); module_exit(fq_pie_module_exit); MODULE_DESCRIPTION("Flow Queue Proportional Integral controller Enhanced (FQ-PIE)"); MODULE_AUTHOR("Mohit P. Tahiliani"); MODULE_LICENSE("GPL");
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