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Message-ID: <20230815092348.1449179-3-francois.michel@uclouvain.be>
Date: Tue, 15 Aug 2023 11:23:39 +0200
From: Francois Michel <francois.michel@...ouvain.be>
To: unlisted-recipients:; (no To-header on input)
Cc: Francois Michel <francois.michel@...ouvain.be>,
Jamal Hadi Salim <jhs@...atatu.com>,
Cong Wang <xiyou.wangcong@...il.com>,
Jiri Pirko <jiri@...nulli.us>,
Stephen Hemminger <stephen@...workplumber.org>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>, netdev@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH v2 net-next 2/3] netem: use a seeded PRNG for generating random losses
From: François Michel <francois.michel@...ouvain.be>
Use prandom_u32_state() instead of get_random_u32() to generate
the random loss events of netem. The state of the prng is part
of the prng attribute of struct netem_sched_data.
Signed-off-by: François Michel <francois.michel@...ouvain.be>
---
net/sched/sch_netem.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 621c6acfd644..8b54b1005a10 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -206,7 +206,7 @@ static u32 get_crandom(struct crndstate *state)
static bool loss_4state(struct netem_sched_data *q)
{
struct clgstate *clg = &q->clg;
- u32 rnd = get_random_u32();
+ u32 rnd = prandom_u32_state(&q->prng.prng_state);
/*
* Makes a comparison between rnd and the transition
@@ -271,18 +271,19 @@ static bool loss_4state(struct netem_sched_data *q)
static bool loss_gilb_ell(struct netem_sched_data *q)
{
struct clgstate *clg = &q->clg;
+ struct rnd_state *s = &q->prng.prng_state;
switch (clg->state) {
case GOOD_STATE:
- if (get_random_u32() < clg->a1)
+ if (prandom_u32_state(s) < clg->a1)
clg->state = BAD_STATE;
- if (get_random_u32() < clg->a4)
+ if (prandom_u32_state(s) < clg->a4)
return true;
break;
case BAD_STATE:
- if (get_random_u32() < clg->a2)
+ if (prandom_u32_state(s) < clg->a2)
clg->state = GOOD_STATE;
- if (get_random_u32() > clg->a3)
+ if (prandom_u32_state(s) > clg->a3)
return true;
}
--
2.41.0
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