fq_codel: should use qdisc backlog as threshold
codel_should_drop() logic allows a packet being not dropped if queue
size is under max packet size.
In fq_codel, we have two possible backlogs : The qdisc global one, and
the flow local one.
The meaningful one for codel_should_drop() should be the global backlog,
not the per flow one, so that thin flows can have a non zero drop/mark
probability.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Dave Taht <dave.taht@bufferbloat.net>
Cc: Kathleen Nichols <nichols@pollere.com>
Cc: Van Jacobson <van@pollere.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/codel.h b/include/net/codel.h
index 7546517..550debf 100644
--- a/include/net/codel.h
+++ b/include/net/codel.h
@@ -205,7 +205,7 @@
static bool codel_should_drop(const struct sk_buff *skb,
- unsigned int *backlog,
+ struct Qdisc *sch,
struct codel_vars *vars,
struct codel_params *params,
struct codel_stats *stats,
@@ -219,13 +219,13 @@
}
vars->ldelay = now - codel_get_enqueue_time(skb);
- *backlog -= qdisc_pkt_len(skb);
+ sch->qstats.backlog -= qdisc_pkt_len(skb);
if (unlikely(qdisc_pkt_len(skb) > stats->maxpacket))
stats->maxpacket = qdisc_pkt_len(skb);
if (codel_time_before(vars->ldelay, params->target) ||
- *backlog <= stats->maxpacket) {
+ sch->qstats.backlog <= stats->maxpacket) {
/* went below - stay below for at least interval */
vars->first_above_time = 0;
return false;
@@ -249,8 +249,7 @@
struct codel_params *params,
struct codel_vars *vars,
struct codel_stats *stats,
- codel_skb_dequeue_t dequeue_func,
- u32 *backlog)
+ codel_skb_dequeue_t dequeue_func)
{
struct sk_buff *skb = dequeue_func(vars, sch);
codel_time_t now;
@@ -261,7 +260,7 @@
return skb;
}
now = codel_get_time();
- drop = codel_should_drop(skb, backlog, vars, params, stats, now);
+ drop = codel_should_drop(skb, sch, vars, params, stats, now);
if (vars->dropping) {
if (!drop) {
/* sojourn time below target - leave dropping state */
@@ -292,7 +291,7 @@
qdisc_drop(skb, sch);
stats->drop_count++;
skb = dequeue_func(vars, sch);
- if (!codel_should_drop(skb, backlog,
+ if (!codel_should_drop(skb, sch,
vars, params, stats, now)) {
/* leave dropping state */
vars->dropping = false;
@@ -313,7 +312,7 @@
stats->drop_count++;
skb = dequeue_func(vars, sch);
- drop = codel_should_drop(skb, backlog, vars, params,
+ drop = codel_should_drop(skb, sch, vars, params,
stats, now);
}
vars->dropping = true;