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Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/sch_fq.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index 5dd929cc1423..18e752439f6f 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -86,6 +86,7 @@ struct fq_sched_data {
struct rb_root delayed; /* for rate limited flows */
u64 time_next_delayed_flow;
+ unsigned long unthrottle_latency_ns;
struct fq_flow internal; /* for non classified or high prio packets */
u32 quantum;
@@ -408,11 +409,19 @@ static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
static void fq_check_throttled(struct fq_sched_data *q, u64 now)
{
+ unsigned long sample;
struct rb_node *p;
if (q->time_next_delayed_flow > now)
return;
+ /* Update unthrottle latency EWMA.
+ * This is cheap and can help diagnosing timer/latency problems.
+ */
+ sample = (unsigned long)(now - q->time_next_delayed_flow);
+ q->unthrottle_latency_ns -= q->unthrottle_latency_ns >> 3;
+ q->unthrottle_latency_ns += sample >> 3;
+
q->time_next_delayed_flow = ~0ULL;
while ((p = rb_first(&q->delayed)) != NULL) {
struct fq_flow *f = container_of(p, struct fq_flow, rate_node);
@@ -515,7 +524,12 @@ begin:
len = NSEC_PER_SEC;
q->stat_pkts_too_long++;
}
-
+ /* Account for schedule/timers drifts.
+ * f->time_next_packet was set when prior packet was sent,
+ * and current time (@now) can be too late by tens of us.
+ */
+ if (f->time_next_packet)
+ len -= min(len/2, now - f->time_next_packet);
f->time_next_packet = now + len;
}
out:
@@ -787,6 +801,7 @@ static int fq_init(struct Qdisc *sch, struct nlattr *opt)
q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch));
q->flow_refill_delay = msecs_to_jiffies(40);
q->flow_max_rate = ~0U;
+ q->time_next_delayed_flow = ~0ULL;
q->rate_enable = 1;
q->new_flows.first = NULL;
q->old_flows.first = NULL;
@@ -854,8 +869,8 @@ static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
st.flows = q->flows;
st.inactive_flows = q->inactive_flows;
st.throttled_flows = q->throttled_flows;
- st.pad = 0;
-
+ st.unthrottle_latency_ns = min_t(unsigned long,
+ q->unthrottle_latency_ns, ~0U);
sch_tree_unlock(sch);
return gnet_stats_copy_app(d, &st, sizeof(st));