[Codel] sprout

[Eric Dumazet]

On Thu, 2013-07-11 at 08:45 -0700, Kathleen Nichols wrote:

> Dave, not completely sure which reservation about maxpacket is in reference.

Hi Kathleen

I believe Dave is referring to the fact that we update maxpacket every
time we dequeue a packet, and with GSO packet it makes little sense
because after a while maxpacket is set to ~65535, the limit of the GSO
packet size.

We might remove this code, and make maxpacket a constant.

diff --git a/include/net/codel.h b/include/net/codel.h
index 389cf62..470e1ff 100644
--- a/include/net/codel.h
+++ b/include/net/codel.h
@@ -170,7 +170,7 @@ static void codel_vars_init(struct codel_vars *vars)
 
 static void codel_stats_init(struct codel_stats *stats)
 {
-       stats->maxpacket = 256;
+       stats->maxpacket = 1500;
 }
 
 /*
@@ -221,9 +221,6 @@ static bool codel_should_drop(const struct sk_buff *skb,
        vars->ldelay = now - codel_get_enqueue_time(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) ||
            sch->qstats.backlog <= stats->maxpacket) {
                /* went below - stay below for at least interval */