From: Dave Taht <[email protected]>
The consensus at ietf was that ecn marking should start at
target, and then the results fed into the codel drop scheduler.
While I agree with the latter, I feel that waiting an interval
before starting to mark will be more in-tune with the concept
of a sojourn time, and lead to better utilization.
As I am outnumbered and outgunned, do it at target.
---
include/net/codel.h | 30 ++++++++++--------------------
1 file changed, 10 insertions(+), 20 deletions(-)
diff --git a/include/net/codel.h b/include/net/codel.h
index 550debf..f06d99c 100644
--- a/include/net/codel.h
+++ b/include/net/codel.h
@@ -204,7 +204,7 @@ static codel_time_t codel_control_law(codel_time_t t,
}
-static bool codel_should_drop(const struct sk_buff *skb,
+static bool codel_should_drop(struct sk_buff *skb,
struct Qdisc *sch,
struct codel_vars *vars,
struct codel_params *params,
@@ -231,6 +231,9 @@ static bool codel_should_drop(const struct sk_buff *skb,
return false;
}
ok_to_drop = false;
+ /* Above target, start marking */
+ if (params->ecn && INET_ECN_set_ce(skb))
+ stats->ecn_mark++;
if (vars->first_above_time == 0) {
/* just went above from below. If we stay above
* for at least interval we'll say it's ok to drop
@@ -238,6 +241,7 @@ static bool codel_should_drop(const struct sk_buff *skb,
vars->first_above_time = now + params->interval;
} else if (codel_time_after(now, vars->first_above_time)) {
ok_to_drop = true;
+ /* dtaht: I think we should start marking here, instead */
}
return ok_to_drop;
}
@@ -280,14 +284,6 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch,
* since there is no more divide
*/
codel_Newton_step(vars);
- if (params->ecn && INET_ECN_set_ce(skb)) {
- stats->ecn_mark++;
- vars->drop_next =
-
codel_control_law(vars->drop_next,
-
params->interval,
-
vars->rec_inv_sqrt);
- goto end;
- }
qdisc_drop(skb, sch);
stats->drop_count++;
skb = dequeue_func(vars, sch);
@@ -305,16 +301,11 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch,
}
}
} else if (drop) {
- if (params->ecn && INET_ECN_set_ce(skb)) {
- stats->ecn_mark++;
- } else {
- qdisc_drop(skb, sch);
- stats->drop_count++;
-
- skb = dequeue_func(vars, sch);
- drop = codel_should_drop(skb, sch, vars, params,
- stats, now);
- }
+ qdisc_drop(skb, sch);
+ stats->drop_count++;
+ skb = dequeue_func(vars, sch);
+ drop = codel_should_drop(skb, sch, vars, params,
+ stats, now);
vars->dropping = true;
/* if min went above target close to when we last went below it
* assume that the drop rate that controlled the queue on the
@@ -336,7 +327,6 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch,
vars->drop_next = codel_control_law(now, params->interval,
vars->rec_inv_sqrt);
}
-end:
return skb;
}
#endif
--
1.7.9.5
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