[PATCH 9/9] netem: restore no jitter option
From: Stephen Hemminger <hidden>
Date: 2010-08-06 19:38:05
Before netem was forced to be classless, it was possible to prevent packet reordering by using a pure FIFO queue. This restores the option, although now it has to be done as a module parameter. Signed-off-by: Stephen Hemminger <redacted>
--- a/net/sched/sch_netem.c 2010-08-02 15:02:36.654303844 -0700
+++ b/net/sched/sch_netem.c 2010-08-02 15:02:59.146459862 -0700@@ -87,6 +87,10 @@ static inline struct netem_skb_cb *netem return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data; } +static int jitter = 1; +module_param(jitter, int, 0); +MODULE_PARM_DESC(jitter, "reorder packets based on delay"); + /* init_crandom - initialize correlated random number generator * Use entropy source for initial seed. */
@@ -531,6 +535,7 @@ static struct Qdisc_ops tfifo_qdisc_ops static int netem_init(struct Qdisc *sch, struct nlattr *opt) { struct netem_sched_data *q = qdisc_priv(sch); + struct Qdisc_ops *ops = jitter ? &tfifo_qdisc_ops : &pfifo_qdisc_ops; int ret; if (!opt)
@@ -539,8 +544,7 @@ static int netem_init(struct Qdisc *sch, qdisc_watchdog_init(&q->watchdog, sch); q->qdisc = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue, - &tfifo_qdisc_ops, - TC_H_MAKE(sch->handle, 1)); + ops, TC_H_MAKE(sch->handle, 1)); if (!q->qdisc) { pr_debug("netem: qdisc create failed\n"); return -ENOMEM;