static struct sk_buff *
sfq_dequeue(struct Qdisc* sch)
{
struct sfq_sched_data *q = (struct sfq_sched_data *)sch->data;
struct sk_buff *skb;
sfq_index a, old_a;
/* No active slots */
if (q->tail == SFQ_DEPTH)
return NULL;
a = old_a = q->next[q->tail];
/* Grab packet */
skb = __skb_dequeue(&q->qs[a]);
sfq_dec(q, a);
sch->q.qlen--;
/* Is the slot empty? */
if (q->qs[a].qlen == 0) {
q->ht[q->hash[a]] = SFQ_DEPTH;
a = q->next[a];
if (a == old_a) {
q->tail = SFQ_DEPTH;
return skb;
}
q->next[q->tail] = a;
q->allot[a] += q->quantum;
} else if ((q->allot[a] -= skb->len) <= 0) {
q->tail = a;
a = q->next[a];
q->allot[a] += q->quantum;
}
return 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--;
sch->qstats.drops++;
sch->qstats.backlog -= len;
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;
}
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;
/* */
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--;
sch->qstats.drops++;
sch->qstats.backlog -= len;
return len;
}
if (d == 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;
}
static unsigned int sfq_drop(struct Qdisc *sch)
{
struct sfq_sched_data *q = qdisc_priv(sch);
sfq_index d = q->max_depth;
struct sk_buff *skb;
unsigned int len;
/* Queue is full! Find the longest slot and
drop a packet from it */
if (d > 1) {
sfq_index x = q->dep[d + SFQ_DEPTH].next;
skb = q->qs[x].prev;
len = skb->len;
__skb_unlink(skb, &q->qs[x]);
kfree_skb(skb);
sfq_dec(q, x);
sch->q.qlen--;
sch->qstats.drops++;
sch->qstats.backlog -= len;
return len;
}
if (d == 1) {
/* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */
d = q->next[q->tail];
q->next[q->tail] = q->next[d];
q->allot[q->next[d]] += q->quantum;
skb = q->qs[d].prev;
len = skb->len;
__skb_unlink(skb, &q->qs[d]);
kfree_skb(skb);
sfq_dec(q, d);
sch->q.qlen--;
q->ht[q->hash[d]] = SFQ_DEPTH;
sch->qstats.drops++;
sch->qstats.backlog -= len;
return len;
}
return 0;
}
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--;
sch->qstats.backlog -= qdisc_pkt_len(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;
}
/*
* 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: sch->qstats.backlog -= qdisc_pkt_len(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);
}
