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Diffstat (limited to 'net/sched/sch_netem.c')
-rw-r--r--net/sched/sch_netem.c33
1 files changed, 29 insertions, 4 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 3bfd733..1fa2f90 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -22,6 +22,7 @@
#include <linux/skbuff.h>
#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
+#include <linux/reciprocal_div.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
@@ -80,6 +81,10 @@ struct netem_sched_data {
u32 reorder;
u32 corrupt;
u32 rate;
+ s32 packet_overhead;
+ u32 cell_size;
+ u32 cell_size_reciprocal;
+ s32 cell_overhead;
struct crndstate {
u32 last;
@@ -299,11 +304,23 @@ static psched_tdiff_t tabledist(psched_tdiff_t mu, psched_tdiff_t sigma,
return x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu;
}
-static psched_time_t packet_len_2_sched_time(unsigned int len, u32 rate)
+static psched_time_t packet_len_2_sched_time(unsigned int len, struct netem_sched_data *q)
{
- u64 ticks = (u64)len * NSEC_PER_SEC;
+ u64 ticks;
- do_div(ticks, rate);
+ len += q->packet_overhead;
+
+ if (q->cell_size) {
+ u32 cells = reciprocal_divide(len, q->cell_size_reciprocal);
+
+ if (len > cells * q->cell_size) /* extra cell needed for remainder */
+ cells++;
+ len = cells * (q->cell_size + q->cell_overhead);
+ }
+
+ ticks = (u64)len * NSEC_PER_SEC;
+
+ do_div(ticks, q->rate);
return PSCHED_NS2TICKS(ticks);
}
@@ -384,7 +401,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
if (q->rate) {
struct sk_buff_head *list = &q->qdisc->q;
- delay += packet_len_2_sched_time(skb->len, q->rate);
+ delay += packet_len_2_sched_time(skb->len, q);
if (!skb_queue_empty(list)) {
/*
@@ -568,6 +585,11 @@ static void get_rate(struct Qdisc *sch, const struct nlattr *attr)
const struct tc_netem_rate *r = nla_data(attr);
q->rate = r->rate;
+ q->packet_overhead = r->packet_overhead;
+ q->cell_size = r->cell_size;
+ if (q->cell_size)
+ q->cell_size_reciprocal = reciprocal_value(q->cell_size);
+ q->cell_overhead = r->cell_overhead;
}
static int get_loss_clg(struct Qdisc *sch, const struct nlattr *attr)
@@ -909,6 +931,9 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
NLA_PUT(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt);
rate.rate = q->rate;
+ rate.packet_overhead = q->packet_overhead;
+ rate.cell_size = q->cell_size;
+ rate.cell_overhead = q->cell_overhead;
NLA_PUT(skb, TCA_NETEM_RATE, sizeof(rate), &rate);
if (dump_loss_model(q, skb) != 0)
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