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-rw-r--r--net/sched/sch_pie.c28
1 files changed, 27 insertions, 1 deletions
diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c
index 30f158582499..916b878d3491 100644
--- a/net/sched/sch_pie.c
+++ b/net/sched/sch_pie.c
@@ -55,8 +55,10 @@ struct pie_vars {
psched_time_t qdelay_old;
u64 dq_count; /* measured in bytes */
psched_time_t dq_tstamp; /* drain rate */
+ u64 accu_prob; /* accumulated drop probability */
u32 avg_dq_rate; /* bytes per pschedtime tick,scaled */
u32 qlen_old; /* in bytes */
+ u8 accu_prob_overflows; /* overflows of accu_prob */
};
/* statistics gathering */
@@ -91,9 +93,11 @@ static void pie_params_init(struct pie_params *params)
static void pie_vars_init(struct pie_vars *vars)
{
vars->dq_count = DQCOUNT_INVALID;
+ vars->accu_prob = 0;
vars->avg_dq_rate = 0;
/* default of 150 ms in pschedtime */
vars->burst_time = PSCHED_NS2TICKS(150 * NSEC_PER_MSEC);
+ vars->accu_prob_overflows = 0;
}
static bool drop_early(struct Qdisc *sch, u32 packet_size)
@@ -128,9 +132,29 @@ static bool drop_early(struct Qdisc *sch, u32 packet_size)
else
local_prob = q->vars.prob;
+ if (local_prob == 0) {
+ q->vars.accu_prob = 0;
+ q->vars.accu_prob_overflows = 0;
+ }
+
+ if (local_prob > MAX_PROB - q->vars.accu_prob)
+ q->vars.accu_prob_overflows++;
+
+ q->vars.accu_prob += local_prob;
+
+ if (q->vars.accu_prob_overflows == 0 &&
+ q->vars.accu_prob < (MAX_PROB / 100) * 85)
+ return false;
+ if (q->vars.accu_prob_overflows == 8 &&
+ q->vars.accu_prob >= MAX_PROB / 2)
+ return true;
+
prandom_bytes(&rnd, 8);
- if (rnd < local_prob)
+ if (rnd < local_prob) {
+ q->vars.accu_prob = 0;
+ q->vars.accu_prob_overflows = 0;
return true;
+ }
return false;
}
@@ -168,6 +192,8 @@ static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
out:
q->stats.dropped++;
+ q->vars.accu_prob = 0;
+ q->vars.accu_prob_overflows = 0;
return qdisc_drop(skb, sch, to_free);
}