From: Leslie Monis <lesliemonis@gmail.com>
Date: Mon, 9 Mar 2020 19:10:33 +0000 (+0530)
Subject: net: sched: pie: change tc_pie_xstats->prob
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3f95f55eb55daa17c047d731d1fb7854e5823478;p=linux.git

net: sched: pie: change tc_pie_xstats->prob

Commit 105e808c1da2 ("pie: remove pie_vars->accu_prob_overflows")
changes the scale of probability values in PIE from (2^64 - 1) to
(2^56 - 1). This affects the precision of tc_pie_xstats->prob in
user space.

This patch ensures user space is unaffected.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Leslie Monis <lesliemonis@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c
index f52442d39bf57..c65077f0c0f39 100644
--- a/net/sched/sch_pie.c
+++ b/net/sched/sch_pie.c
@@ -493,7 +493,7 @@ static int pie_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
 {
 	struct pie_sched_data *q = qdisc_priv(sch);
 	struct tc_pie_xstats st = {
-		.prob		= q->vars.prob,
+		.prob		= q->vars.prob << BITS_PER_BYTE,
 		.delay		= ((u32)PSCHED_TICKS2NS(q->vars.qdelay)) /
 				   NSEC_PER_USEC,
 		.packets_in	= q->stats.packets_in,