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Diffstat (limited to 'net/sched/sch_sfq.c')
-rw-r--r--net/sched/sch_sfq.c53
1 files changed, 34 insertions, 19 deletions
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 95795730985..b542c875e15 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -19,6 +19,7 @@
#include <linux/init.h>
#include <linux/ipv6.h>
#include <linux/skbuff.h>
+#include <linux/jhash.h>
#include <net/ip.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
@@ -95,7 +96,7 @@ struct sfq_sched_data
/* Variables */
struct timer_list perturb_timer;
- int perturbation;
+ u32 perturbation;
sfq_index tail; /* Index of current slot in round */
sfq_index max_depth; /* Maximal depth */
@@ -109,12 +110,7 @@ struct sfq_sched_data
static __inline__ unsigned sfq_fold_hash(struct sfq_sched_data *q, u32 h, u32 h1)
{
- int pert = q->perturbation;
-
- /* Have we any rotation primitives? If not, WHY? */
- h ^= (h1<<pert) ^ (h1>>(0x1F - pert));
- h ^= h>>10;
- return h & 0x3FF;
+ return jhash_2words(h, h1, q->perturbation) & (SFQ_HASH_DIVISOR - 1);
}
static unsigned sfq_hash(struct sfq_sched_data *q, struct sk_buff *skb)
@@ -256,6 +252,13 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc* sch)
q->ht[hash] = x = q->dep[SFQ_DEPTH].next;
q->hash[x] = hash;
}
+ /* If selected queue has length q->limit, this means that
+ * all another queues are empty and that we do simple tail drop,
+ * i.e. drop _this_ packet.
+ */
+ if (q->qs[x].qlen >= q->limit)
+ return qdisc_drop(skb, sch);
+
sch->qstats.backlog += skb->len;
__skb_queue_tail(&q->qs[x], skb);
sfq_inc(q, x);
@@ -270,7 +273,7 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc* sch)
q->tail = x;
}
}
- if (++sch->q.qlen < q->limit-1) {
+ if (++sch->q.qlen <= q->limit) {
sch->bstats.bytes += skb->len;
sch->bstats.packets++;
return 0;
@@ -294,6 +297,19 @@ sfq_requeue(struct sk_buff *skb, struct Qdisc* sch)
}
sch->qstats.backlog += skb->len;
__skb_queue_head(&q->qs[x], skb);
+ /* If selected queue has length q->limit+1, this means that
+ * all another queues are empty and we do simple tail drop.
+ * This packet is still requeued at head of queue, tail packet
+ * is dropped.
+ */
+ if (q->qs[x].qlen > q->limit) {
+ skb = q->qs[x].prev;
+ __skb_unlink(skb, &q->qs[x]);
+ sch->qstats.drops++;
+ sch->qstats.backlog -= skb->len;
+ kfree_skb(skb);
+ return NET_XMIT_CN;
+ }
sfq_inc(q, x);
if (q->qs[x].qlen == 1) { /* The flow is new */
if (q->tail == SFQ_DEPTH) { /* It is the first flow */
@@ -306,7 +322,7 @@ sfq_requeue(struct sk_buff *skb, struct Qdisc* sch)
q->tail = x;
}
}
- if (++sch->q.qlen < q->limit - 1) {
+ if (++sch->q.qlen <= q->limit) {
sch->qstats.requeues++;
return 0;
}
@@ -370,12 +386,10 @@ static void sfq_perturbation(unsigned long arg)
struct Qdisc *sch = (struct Qdisc*)arg;
struct sfq_sched_data *q = qdisc_priv(sch);
- q->perturbation = net_random()&0x1F;
+ get_random_bytes(&q->perturbation, 4);
- if (q->perturb_period) {
- q->perturb_timer.expires = jiffies + q->perturb_period;
- add_timer(&q->perturb_timer);
- }
+ if (q->perturb_period)
+ mod_timer(&q->perturb_timer, jiffies + q->perturb_period);
}
static int sfq_change(struct Qdisc *sch, struct rtattr *opt)
@@ -391,17 +405,17 @@ static int sfq_change(struct Qdisc *sch, struct rtattr *opt)
q->quantum = ctl->quantum ? : psched_mtu(sch->dev);
q->perturb_period = ctl->perturb_period*HZ;
if (ctl->limit)
- q->limit = min_t(u32, ctl->limit, SFQ_DEPTH);
+ q->limit = min_t(u32, ctl->limit, SFQ_DEPTH - 1);
qlen = sch->q.qlen;
- while (sch->q.qlen >= q->limit-1)
+ 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) {
- q->perturb_timer.expires = jiffies + q->perturb_period;
- add_timer(&q->perturb_timer);
+ mod_timer(&q->perturb_timer, jiffies + q->perturb_period);
+ get_random_bytes(&q->perturbation, 4);
}
sch_tree_unlock(sch);
return 0;
@@ -423,12 +437,13 @@ static int sfq_init(struct Qdisc *sch, struct rtattr *opt)
q->dep[i+SFQ_DEPTH].next = i+SFQ_DEPTH;
q->dep[i+SFQ_DEPTH].prev = i+SFQ_DEPTH;
}
- q->limit = SFQ_DEPTH;
+ q->limit = SFQ_DEPTH - 1;
q->max_depth = 0;
q->tail = SFQ_DEPTH;
if (opt == NULL) {
q->quantum = psched_mtu(sch->dev);
q->perturb_period = 0;
+ get_random_bytes(&q->perturbation, 4);
} else {
int err = sfq_change(sch, opt);
if (err)