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Diffstat (limited to 'kernel/net/sched/sch_sfq.c')
| -rw-r--r-- | kernel/net/sched/sch_sfq.c | 939 |
1 files changed, 939 insertions, 0 deletions
diff --git a/kernel/net/sched/sch_sfq.c b/kernel/net/sched/sch_sfq.c new file mode 100644 index 000000000..b877140be --- /dev/null +++ b/kernel/net/sched/sch_sfq.c @@ -0,0 +1,939 @@ +/* + * net/sched/sch_sfq.c Stochastic Fairness Queueing discipline. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/string.h> +#include <linux/in.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/skbuff.h> +#include <linux/jhash.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <net/netlink.h> +#include <net/pkt_sched.h> +#include <net/flow_keys.h> +#include <net/red.h> + + +/* Stochastic Fairness Queuing algorithm. + ======================================= + + Source: + Paul E. McKenney "Stochastic Fairness Queuing", + IEEE INFOCOMM'90 Proceedings, San Francisco, 1990. + + Paul E. McKenney "Stochastic Fairness Queuing", + "Interworking: Research and Experience", v.2, 1991, p.113-131. + + + See also: + M. Shreedhar and George Varghese "Efficient Fair + Queuing using Deficit Round Robin", Proc. SIGCOMM 95. + + + This is not the thing that is usually called (W)FQ nowadays. + It does not use any timestamp mechanism, but instead + processes queues in round-robin order. + + ADVANTAGE: + + - It is very cheap. Both CPU and memory requirements are minimal. + + DRAWBACKS: + + - "Stochastic" -> It is not 100% fair. + When hash collisions occur, several flows are considered as one. + + - "Round-robin" -> It introduces larger delays than virtual clock + based schemes, and should not be used for isolating interactive + traffic from non-interactive. It means, that this scheduler + should be used as leaf of CBQ or P3, which put interactive traffic + to higher priority band. + + We still need true WFQ for top level CSZ, but using WFQ + for the best effort traffic is absolutely pointless: + SFQ is superior for this purpose. + + IMPLEMENTATION: + This implementation limits : + - maximal queue length per flow to 127 packets. + - max mtu to 2^18-1; + - max 65408 flows, + - number of hash buckets to 65536. + + It is easy to increase these values, but not in flight. */ + +#define SFQ_MAX_DEPTH 127 /* max number of packets per flow */ +#define SFQ_DEFAULT_FLOWS 128 +#define SFQ_MAX_FLOWS (0x10000 - SFQ_MAX_DEPTH - 1) /* max number of flows */ +#define SFQ_EMPTY_SLOT 0xffff +#define SFQ_DEFAULT_HASH_DIVISOR 1024 + +/* We use 16 bits to store allot, and want to handle packets up to 64K + * Scale allot by 8 (1<<3) so that no overflow occurs. + */ +#define SFQ_ALLOT_SHIFT 3 +#define SFQ_ALLOT_SIZE(X) DIV_ROUND_UP(X, 1 << SFQ_ALLOT_SHIFT) + +/* This type should contain at least SFQ_MAX_DEPTH + 1 + SFQ_MAX_FLOWS values */ +typedef u16 sfq_index; + +/* + * We dont use pointers to save space. + * Small indexes [0 ... SFQ_MAX_FLOWS - 1] are 'pointers' to slots[] array + * while following values [SFQ_MAX_FLOWS ... SFQ_MAX_FLOWS + SFQ_MAX_DEPTH] + * are 'pointers' to dep[] array + */ +struct sfq_head { + sfq_index next; + sfq_index prev; +}; + +struct sfq_slot { + struct sk_buff *skblist_next; + struct sk_buff *skblist_prev; + sfq_index qlen; /* number of skbs in skblist */ + sfq_index next; /* next slot in sfq RR chain */ + struct sfq_head dep; /* anchor in dep[] chains */ + unsigned short hash; /* hash value (index in ht[]) */ + short allot; /* credit for this slot */ + + unsigned int backlog; + struct red_vars vars; +}; + +struct sfq_sched_data { +/* frequently used fields */ + int limit; /* limit of total number of packets in this qdisc */ + unsigned int divisor; /* number of slots in hash table */ + u8 headdrop; + u8 maxdepth; /* limit of packets per flow */ + + u32 perturbation; + u8 cur_depth; /* depth of longest slot */ + u8 flags; + unsigned short scaled_quantum; /* SFQ_ALLOT_SIZE(quantum) */ + struct tcf_proto __rcu *filter_list; + sfq_index *ht; /* Hash table ('divisor' slots) */ + struct sfq_slot *slots; /* Flows table ('maxflows' entries) */ + + struct red_parms *red_parms; + struct tc_sfqred_stats stats; + struct sfq_slot *tail; /* current slot in round */ + + struct sfq_head dep[SFQ_MAX_DEPTH + 1]; + /* Linked lists of slots, indexed by depth + * dep[0] : list of unused flows + * dep[1] : list of flows with 1 packet + * dep[X] : list of flows with X packets + */ + + unsigned int maxflows; /* number of flows in flows array */ + int perturb_period; + unsigned int quantum; /* Allotment per round: MUST BE >= MTU */ + struct timer_list perturb_timer; +}; + +/* + * sfq_head are either in a sfq_slot or in dep[] array + */ +static inline struct sfq_head *sfq_dep_head(struct sfq_sched_data *q, sfq_index val) +{ + if (val < SFQ_MAX_FLOWS) + return &q->slots[val].dep; + return &q->dep[val - SFQ_MAX_FLOWS]; +} + +/* + * In order to be able to quickly rehash our queue when timer changes + * q->perturbation, we store flow_keys in skb->cb[] + */ +struct sfq_skb_cb { + struct flow_keys keys; +}; + +static inline struct sfq_skb_cb *sfq_skb_cb(const struct sk_buff *skb) +{ + qdisc_cb_private_validate(skb, sizeof(struct sfq_skb_cb)); + return (struct sfq_skb_cb *)qdisc_skb_cb(skb)->data; +} + +static unsigned int sfq_hash(const struct sfq_sched_data *q, + const struct sk_buff *skb) +{ + const struct flow_keys *keys = &sfq_skb_cb(skb)->keys; + unsigned int hash; + + hash = jhash_3words((__force u32)keys->dst, + (__force u32)keys->src ^ keys->ip_proto, + (__force u32)keys->ports, q->perturbation); + return hash & (q->divisor - 1); +} + +static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch, + int *qerr) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + struct tcf_result res; + struct tcf_proto *fl; + int result; + + if (TC_H_MAJ(skb->priority) == sch->handle && + TC_H_MIN(skb->priority) > 0 && + TC_H_MIN(skb->priority) <= q->divisor) + return TC_H_MIN(skb->priority); + + fl = rcu_dereference_bh(q->filter_list); + if (!fl) { + skb_flow_dissect(skb, &sfq_skb_cb(skb)->keys); + return sfq_hash(q, skb) + 1; + } + + *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; + result = tc_classify(skb, fl, &res); + if (result >= 0) { +#ifdef CONFIG_NET_CLS_ACT + switch (result) { + case TC_ACT_STOLEN: + case TC_ACT_QUEUED: + *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; + case TC_ACT_SHOT: + return 0; + } +#endif + if (TC_H_MIN(res.classid) <= q->divisor) + return TC_H_MIN(res.classid); + } + return 0; +} + +/* + * x : slot number [0 .. SFQ_MAX_FLOWS - 1] + */ +static inline void sfq_link(struct sfq_sched_data *q, sfq_index x) +{ + sfq_index p, n; + struct sfq_slot *slot = &q->slots[x]; + int qlen = slot->qlen; + + p = qlen + SFQ_MAX_FLOWS; + n = q->dep[qlen].next; + + slot->dep.next = n; + slot->dep.prev = p; + + q->dep[qlen].next = x; /* sfq_dep_head(q, p)->next = x */ + sfq_dep_head(q, n)->prev = x; +} + +#define sfq_unlink(q, x, n, p) \ + do { \ + n = q->slots[x].dep.next; \ + p = q->slots[x].dep.prev; \ + sfq_dep_head(q, p)->next = n; \ + sfq_dep_head(q, n)->prev = p; \ + } while (0) + + +static inline void sfq_dec(struct sfq_sched_data *q, sfq_index x) +{ + sfq_index p, n; + int d; + + sfq_unlink(q, x, n, p); + + d = q->slots[x].qlen--; + if (n == p && q->cur_depth == d) + q->cur_depth--; + sfq_link(q, x); +} + +static inline void sfq_inc(struct sfq_sched_data *q, sfq_index x) +{ + sfq_index p, n; + int d; + + sfq_unlink(q, x, n, p); + + d = ++q->slots[x].qlen; + if (q->cur_depth < d) + q->cur_depth = d; + sfq_link(q, x); +} + +/* helper functions : might be changed when/if skb use a standard list_head */ + +/* remove one skb from tail of slot queue */ +static inline struct sk_buff *slot_dequeue_tail(struct sfq_slot *slot) +{ + struct sk_buff *skb = slot->skblist_prev; + + slot->skblist_prev = skb->prev; + skb->prev->next = (struct sk_buff *)slot; + skb->next = skb->prev = NULL; + return skb; +} + +/* remove one skb from head of slot queue */ +static inline struct sk_buff *slot_dequeue_head(struct sfq_slot *slot) +{ + struct sk_buff *skb = slot->skblist_next; + + slot->skblist_next = skb->next; + skb->next->prev = (struct sk_buff *)slot; + skb->next = skb->prev = NULL; + return skb; +} + +static inline void slot_queue_init(struct sfq_slot *slot) +{ + memset(slot, 0, sizeof(*slot)); + slot->skblist_prev = slot->skblist_next = (struct sk_buff *)slot; +} + +/* add skb to slot queue (tail add) */ +static inline void slot_queue_add(struct sfq_slot *slot, struct sk_buff *skb) +{ + skb->prev = slot->skblist_prev; + skb->next = (struct sk_buff *)slot; + slot->skblist_prev->next = skb; + slot->skblist_prev = skb; +} + +static unsigned int sfq_drop(struct Qdisc *sch) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + sfq_index x, d = q->cur_depth; + struct sk_buff *skb; + unsigned int len; + struct sfq_slot *slot; + + /* Queue is full! Find the longest slot and drop tail packet from it */ + if (d > 1) { + x = q->dep[d].next; + slot = &q->slots[x]; +drop: + skb = q->headdrop ? slot_dequeue_head(slot) : slot_dequeue_tail(slot); + len = qdisc_pkt_len(skb); + slot->backlog -= len; + sfq_dec(q, x); + kfree_skb(skb); + sch->q.qlen--; + qdisc_qstats_drop(sch); + qdisc_qstats_backlog_dec(sch, skb); + return len; + } + + if (d == 1) { + /* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */ + x = q->tail->next; + slot = &q->slots[x]; + q->tail->next = slot->next; + q->ht[slot->hash] = SFQ_EMPTY_SLOT; + goto drop; + } + + return 0; +} + +/* Is ECN parameter configured */ +static int sfq_prob_mark(const struct sfq_sched_data *q) +{ + return q->flags & TC_RED_ECN; +} + +/* Should packets over max threshold just be marked */ +static int sfq_hard_mark(const struct sfq_sched_data *q) +{ + return (q->flags & (TC_RED_ECN | TC_RED_HARDDROP)) == TC_RED_ECN; +} + +static int sfq_headdrop(const struct sfq_sched_data *q) +{ + return q->headdrop; +} + +static int +sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + unsigned int hash; + sfq_index x, qlen; + struct sfq_slot *slot; + int uninitialized_var(ret); + struct sk_buff *head; + int delta; + + hash = sfq_classify(skb, sch, &ret); + if (hash == 0) { + if (ret & __NET_XMIT_BYPASS) + qdisc_qstats_drop(sch); + kfree_skb(skb); + return ret; + } + hash--; + + x = q->ht[hash]; + slot = &q->slots[x]; + if (x == SFQ_EMPTY_SLOT) { + x = q->dep[0].next; /* get a free slot */ + if (x >= SFQ_MAX_FLOWS) + return qdisc_drop(skb, sch); + q->ht[hash] = x; + slot = &q->slots[x]; + slot->hash = hash; + slot->backlog = 0; /* should already be 0 anyway... */ + red_set_vars(&slot->vars); + goto enqueue; + } + if (q->red_parms) { + slot->vars.qavg = red_calc_qavg_no_idle_time(q->red_parms, + &slot->vars, + slot->backlog); + switch (red_action(q->red_parms, + &slot->vars, + slot->vars.qavg)) { + case RED_DONT_MARK: + break; + + case RED_PROB_MARK: + qdisc_qstats_overlimit(sch); + if (sfq_prob_mark(q)) { + /* We know we have at least one packet in queue */ + if (sfq_headdrop(q) && + INET_ECN_set_ce(slot->skblist_next)) { + q->stats.prob_mark_head++; + break; + } + if (INET_ECN_set_ce(skb)) { + q->stats.prob_mark++; + break; + } + } + q->stats.prob_drop++; + goto congestion_drop; + + case RED_HARD_MARK: + qdisc_qstats_overlimit(sch); + if (sfq_hard_mark(q)) { + /* We know we have at least one packet in queue */ + if (sfq_headdrop(q) && + INET_ECN_set_ce(slot->skblist_next)) { + q->stats.forced_mark_head++; + break; + } + if (INET_ECN_set_ce(skb)) { + q->stats.forced_mark++; + break; + } + } + q->stats.forced_drop++; + goto congestion_drop; + } + } + + if (slot->qlen >= q->maxdepth) { +congestion_drop: + if (!sfq_headdrop(q)) + return qdisc_drop(skb, sch); + + /* We know we have at least one packet in queue */ + head = slot_dequeue_head(slot); + delta = qdisc_pkt_len(head) - qdisc_pkt_len(skb); + sch->qstats.backlog -= delta; + slot->backlog -= delta; + qdisc_drop(head, sch); + + slot_queue_add(slot, skb); + return NET_XMIT_CN; + } + +enqueue: + qdisc_qstats_backlog_inc(sch, skb); + slot->backlog += qdisc_pkt_len(skb); + slot_queue_add(slot, skb); + sfq_inc(q, x); + if (slot->qlen == 1) { /* The flow is new */ + if (q->tail == NULL) { /* It is the first flow */ + slot->next = x; + } else { + slot->next = q->tail->next; + q->tail->next = x; + } + /* We put this flow at the end of our flow list. + * This might sound unfair for a new flow to wait after old ones, + * but we could endup servicing new flows only, and freeze old ones. + */ + q->tail = slot; + /* We could use a bigger initial quantum for new flows */ + slot->allot = q->scaled_quantum; + } + if (++sch->q.qlen <= q->limit) + return NET_XMIT_SUCCESS; + + qlen = slot->qlen; + sfq_drop(sch); + /* Return Congestion Notification only if we dropped a packet + * from this flow. + */ + if (qlen != slot->qlen) + return NET_XMIT_CN; + + /* As we dropped a packet, better let upper stack know this */ + qdisc_tree_decrease_qlen(sch, 1); + return NET_XMIT_SUCCESS; +} + +static struct sk_buff * +sfq_dequeue(struct Qdisc *sch) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + struct sk_buff *skb; + sfq_index a, next_a; + struct sfq_slot *slot; + + /* No active slots */ + if (q->tail == NULL) + return NULL; + +next_slot: + a = q->tail->next; + slot = &q->slots[a]; + if (slot->allot <= 0) { + q->tail = slot; + slot->allot += q->scaled_quantum; + goto next_slot; + } + skb = slot_dequeue_head(slot); + sfq_dec(q, a); + qdisc_bstats_update(sch, skb); + sch->q.qlen--; + qdisc_qstats_backlog_dec(sch, skb); + slot->backlog -= qdisc_pkt_len(skb); + /* Is the slot empty? */ + if (slot->qlen == 0) { + q->ht[slot->hash] = SFQ_EMPTY_SLOT; + next_a = slot->next; + if (a == next_a) { + q->tail = NULL; /* no more active slots */ + return skb; + } + q->tail->next = next_a; + } else { + slot->allot -= SFQ_ALLOT_SIZE(qdisc_pkt_len(skb)); + } + return skb; +} + +static void +sfq_reset(struct Qdisc *sch) +{ + struct sk_buff *skb; + + while ((skb = sfq_dequeue(sch)) != NULL) + kfree_skb(skb); +} + +/* + * When q->perturbation is changed, we rehash all queued skbs + * to avoid OOO (Out Of Order) effects. + * We dont use sfq_dequeue()/sfq_enqueue() because we dont want to change + * counters. + */ +static void sfq_rehash(struct Qdisc *sch) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + struct sk_buff *skb; + int i; + struct sfq_slot *slot; + struct sk_buff_head list; + int dropped = 0; + + __skb_queue_head_init(&list); + + for (i = 0; i < q->maxflows; i++) { + slot = &q->slots[i]; + if (!slot->qlen) + continue; + while (slot->qlen) { + skb = slot_dequeue_head(slot); + sfq_dec(q, i); + __skb_queue_tail(&list, skb); + } + slot->backlog = 0; + red_set_vars(&slot->vars); + q->ht[slot->hash] = SFQ_EMPTY_SLOT; + } + q->tail = NULL; + + while ((skb = __skb_dequeue(&list)) != NULL) { + unsigned int hash = sfq_hash(q, skb); + sfq_index x = q->ht[hash]; + + slot = &q->slots[x]; + if (x == SFQ_EMPTY_SLOT) { + x = q->dep[0].next; /* get a free slot */ + if (x >= SFQ_MAX_FLOWS) { +drop: + qdisc_qstats_backlog_dec(sch, skb); + kfree_skb(skb); + dropped++; + continue; + } + q->ht[hash] = x; + slot = &q->slots[x]; + slot->hash = hash; + } + if (slot->qlen >= q->maxdepth) + goto drop; + slot_queue_add(slot, skb); + if (q->red_parms) + slot->vars.qavg = red_calc_qavg(q->red_parms, + &slot->vars, + slot->backlog); + slot->backlog += qdisc_pkt_len(skb); + sfq_inc(q, x); + if (slot->qlen == 1) { /* The flow is new */ + if (q->tail == NULL) { /* It is the first flow */ + slot->next = x; + } else { + slot->next = q->tail->next; + q->tail->next = x; + } + q->tail = slot; + slot->allot = q->scaled_quantum; + } + } + sch->q.qlen -= dropped; + qdisc_tree_decrease_qlen(sch, dropped); +} + +static void sfq_perturbation(unsigned long arg) +{ + struct Qdisc *sch = (struct Qdisc *)arg; + struct sfq_sched_data *q = qdisc_priv(sch); + spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); + + spin_lock(root_lock); + q->perturbation = prandom_u32(); + if (!q->filter_list && q->tail) + sfq_rehash(sch); + spin_unlock(root_lock); + + if (q->perturb_period) + mod_timer(&q->perturb_timer, jiffies + q->perturb_period); +} + +static int sfq_change(struct Qdisc *sch, struct nlattr *opt) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + struct tc_sfq_qopt *ctl = nla_data(opt); + struct tc_sfq_qopt_v1 *ctl_v1 = NULL; + unsigned int qlen; + struct red_parms *p = NULL; + + if (opt->nla_len < nla_attr_size(sizeof(*ctl))) + return -EINVAL; + if (opt->nla_len >= nla_attr_size(sizeof(*ctl_v1))) + ctl_v1 = nla_data(opt); + if (ctl->divisor && + (!is_power_of_2(ctl->divisor) || ctl->divisor > 65536)) + return -EINVAL; + if (ctl_v1 && ctl_v1->qth_min) { + p = kmalloc(sizeof(*p), GFP_KERNEL); + if (!p) + return -ENOMEM; + } + sch_tree_lock(sch); + if (ctl->quantum) { + q->quantum = ctl->quantum; + q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum); + } + q->perturb_period = ctl->perturb_period * HZ; + if (ctl->flows) + q->maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS); + if (ctl->divisor) { + q->divisor = ctl->divisor; + q->maxflows = min_t(u32, q->maxflows, q->divisor); + } + if (ctl_v1) { + if (ctl_v1->depth) + q->maxdepth = min_t(u32, ctl_v1->depth, SFQ_MAX_DEPTH); + if (p) { + swap(q->red_parms, p); + red_set_parms(q->red_parms, + ctl_v1->qth_min, ctl_v1->qth_max, + ctl_v1->Wlog, + ctl_v1->Plog, ctl_v1->Scell_log, + NULL, + ctl_v1->max_P); + } + q->flags = ctl_v1->flags; + q->headdrop = ctl_v1->headdrop; + } + if (ctl->limit) { + q->limit = min_t(u32, ctl->limit, q->maxdepth * q->maxflows); + q->maxflows = min_t(u32, q->maxflows, q->limit); + } + + qlen = sch->q.qlen; + while (sch->q.qlen > q->limit) + sfq_drop(sch); + qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen); + + del_timer(&q->perturb_timer); + if (q->perturb_period) { + mod_timer(&q->perturb_timer, jiffies + q->perturb_period); + q->perturbation = prandom_u32(); + } + sch_tree_unlock(sch); + kfree(p); + return 0; +} + +static void *sfq_alloc(size_t sz) +{ + void *ptr = kmalloc(sz, GFP_KERNEL | __GFP_NOWARN); + + if (!ptr) + ptr = vmalloc(sz); + return ptr; +} + +static void sfq_free(void *addr) +{ + kvfree(addr); +} + +static void sfq_destroy(struct Qdisc *sch) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + + tcf_destroy_chain(&q->filter_list); + q->perturb_period = 0; + del_timer_sync(&q->perturb_timer); + sfq_free(q->ht); + sfq_free(q->slots); + kfree(q->red_parms); +} + +static int sfq_init(struct Qdisc *sch, struct nlattr *opt) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + int i; + + q->perturb_timer.function = sfq_perturbation; + q->perturb_timer.data = (unsigned long)sch; + init_timer_deferrable(&q->perturb_timer); + + for (i = 0; i < SFQ_MAX_DEPTH + 1; i++) { + q->dep[i].next = i + SFQ_MAX_FLOWS; + q->dep[i].prev = i + SFQ_MAX_FLOWS; + } + + q->limit = SFQ_MAX_DEPTH; + q->maxdepth = SFQ_MAX_DEPTH; + q->cur_depth = 0; + q->tail = NULL; + q->divisor = SFQ_DEFAULT_HASH_DIVISOR; + q->maxflows = SFQ_DEFAULT_FLOWS; + q->quantum = psched_mtu(qdisc_dev(sch)); + q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum); + q->perturb_period = 0; + q->perturbation = prandom_u32(); + + if (opt) { + int err = sfq_change(sch, opt); + if (err) + return err; + } + + q->ht = sfq_alloc(sizeof(q->ht[0]) * q->divisor); + q->slots = sfq_alloc(sizeof(q->slots[0]) * q->maxflows); + if (!q->ht || !q->slots) { + sfq_destroy(sch); + return -ENOMEM; + } + for (i = 0; i < q->divisor; i++) + q->ht[i] = SFQ_EMPTY_SLOT; + + for (i = 0; i < q->maxflows; i++) { + slot_queue_init(&q->slots[i]); + sfq_link(q, i); + } + if (q->limit >= 1) + sch->flags |= TCQ_F_CAN_BYPASS; + else + sch->flags &= ~TCQ_F_CAN_BYPASS; + return 0; +} + +static int sfq_dump(struct Qdisc *sch, struct sk_buff *skb) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + unsigned char *b = skb_tail_pointer(skb); + struct tc_sfq_qopt_v1 opt; + struct red_parms *p = q->red_parms; + + memset(&opt, 0, sizeof(opt)); + opt.v0.quantum = q->quantum; + opt.v0.perturb_period = q->perturb_period / HZ; + opt.v0.limit = q->limit; + opt.v0.divisor = q->divisor; + opt.v0.flows = q->maxflows; + opt.depth = q->maxdepth; + opt.headdrop = q->headdrop; + + if (p) { + opt.qth_min = p->qth_min >> p->Wlog; + opt.qth_max = p->qth_max >> p->Wlog; + opt.Wlog = p->Wlog; + opt.Plog = p->Plog; + opt.Scell_log = p->Scell_log; + opt.max_P = p->max_P; + } + memcpy(&opt.stats, &q->stats, sizeof(opt.stats)); + opt.flags = q->flags; + + if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) + goto nla_put_failure; + + return skb->len; + +nla_put_failure: + nlmsg_trim(skb, b); + return -1; +} + +static struct Qdisc *sfq_leaf(struct Qdisc *sch, unsigned long arg) +{ + return NULL; +} + +static unsigned long sfq_get(struct Qdisc *sch, u32 classid) +{ + return 0; +} + +static unsigned long sfq_bind(struct Qdisc *sch, unsigned long parent, + u32 classid) +{ + /* we cannot bypass queue discipline anymore */ + sch->flags &= ~TCQ_F_CAN_BYPASS; + return 0; +} + +static void sfq_put(struct Qdisc *q, unsigned long cl) +{ +} + +static struct tcf_proto __rcu **sfq_find_tcf(struct Qdisc *sch, + unsigned long cl) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + + if (cl) + return NULL; + return &q->filter_list; +} + +static int sfq_dump_class(struct Qdisc *sch, unsigned long cl, + struct sk_buff *skb, struct tcmsg *tcm) +{ + tcm->tcm_handle |= TC_H_MIN(cl); + return 0; +} + +static int sfq_dump_class_stats(struct Qdisc *sch, unsigned long cl, + struct gnet_dump *d) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + sfq_index idx = q->ht[cl - 1]; + struct gnet_stats_queue qs = { 0 }; + struct tc_sfq_xstats xstats = { 0 }; + + if (idx != SFQ_EMPTY_SLOT) { + const struct sfq_slot *slot = &q->slots[idx]; + + xstats.allot = slot->allot << SFQ_ALLOT_SHIFT; + qs.qlen = slot->qlen; + qs.backlog = slot->backlog; + } + if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) + return -1; + return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); +} + +static void sfq_walk(struct Qdisc *sch, struct qdisc_walker *arg) +{ + struct sfq_sched_data *q = qdisc_priv(sch); + unsigned int i; + + if (arg->stop) + return; + + for (i = 0; i < q->divisor; i++) { + if (q->ht[i] == SFQ_EMPTY_SLOT || + arg->count < arg->skip) { + arg->count++; + continue; + } + if (arg->fn(sch, i + 1, arg) < 0) { + arg->stop = 1; + break; + } + arg->count++; + } +} + +static const struct Qdisc_class_ops sfq_class_ops = { + .leaf = sfq_leaf, + .get = sfq_get, + .put = sfq_put, + .tcf_chain = sfq_find_tcf, + .bind_tcf = sfq_bind, + .unbind_tcf = sfq_put, + .dump = sfq_dump_class, + .dump_stats = sfq_dump_class_stats, + .walk = sfq_walk, +}; + +static struct Qdisc_ops sfq_qdisc_ops __read_mostly = { + .cl_ops = &sfq_class_ops, + .id = "sfq", + .priv_size = sizeof(struct sfq_sched_data), + .enqueue = sfq_enqueue, + .dequeue = sfq_dequeue, + .peek = qdisc_peek_dequeued, + .drop = sfq_drop, + .init = sfq_init, + .reset = sfq_reset, + .destroy = sfq_destroy, + .change = NULL, + .dump = sfq_dump, + .owner = THIS_MODULE, +}; + +static int __init sfq_module_init(void) +{ + return register_qdisc(&sfq_qdisc_ops); +} +static void __exit sfq_module_exit(void) +{ + unregister_qdisc(&sfq_qdisc_ops); +} +module_init(sfq_module_init) +module_exit(sfq_module_exit) +MODULE_LICENSE("GPL"); |