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authorDave Taht <dave.taht@gmail.com>2017-11-08 15:12:27 -0800
committerDavid S. Miller <davem@davemloft.net>2017-11-13 10:15:47 +0900
commit99803171ef04037092bf5eb29ae801e8b4d49a75 (patch)
tree25d08ba17e1910ffc0f2c7dd0ce9fafcc90bbb01
parent112f9cb65643caf7b922e1a66dc752bfab40aeb1 (diff)
netem: add uapi to express delay and jitter in nanoseconds
netem userspace has long relied on a horrible /proc/net/psched hack to translate the current notion of "ticks" to nanoseconds. Expressing latency and jitter instead, in well defined nanoseconds, increases the dynamic range of emulated delays and jitter in netem. It will also ease a transition where reducing a tick to nsec equivalence would constrain the max delay in prior versions of netem to only 4.3 seconds. Signed-off-by: Dave Taht <dave.taht@gmail.com> Suggested-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/uapi/linux/pkt_sched.h2
-rw-r--r--net/sched/sch_netem.c14
2 files changed, 16 insertions, 0 deletions
diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index 6a2c5ea7e9c4..8fe6d1842bee 100644
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -537,6 +537,8 @@ enum {
TCA_NETEM_ECN,
TCA_NETEM_RATE64,
TCA_NETEM_PAD,
+ TCA_NETEM_LATENCY64,
+ TCA_NETEM_JITTER64,
__TCA_NETEM_MAX,
};
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index e64e0e0d94ff..47d6decba0ea 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -819,6 +819,8 @@ static const struct nla_policy netem_policy[TCA_NETEM_MAX + 1] = {
[TCA_NETEM_LOSS] = { .type = NLA_NESTED },
[TCA_NETEM_ECN] = { .type = NLA_U32 },
[TCA_NETEM_RATE64] = { .type = NLA_U64 },
+ [TCA_NETEM_LATENCY64] = { .type = NLA_S64 },
+ [TCA_NETEM_JITTER64] = { .type = NLA_S64 },
};
static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
@@ -916,6 +918,12 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt)
q->rate = max_t(u64, q->rate,
nla_get_u64(tb[TCA_NETEM_RATE64]));
+ if (tb[TCA_NETEM_LATENCY64])
+ q->latency = nla_get_s64(tb[TCA_NETEM_LATENCY64]);
+
+ if (tb[TCA_NETEM_JITTER64])
+ q->jitter = nla_get_s64(tb[TCA_NETEM_JITTER64]);
+
if (tb[TCA_NETEM_ECN])
q->ecn = nla_get_u32(tb[TCA_NETEM_ECN]);
@@ -1020,6 +1028,12 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
goto nla_put_failure;
+ if (nla_put(skb, TCA_NETEM_LATENCY64, sizeof(q->latency), &q->latency))
+ goto nla_put_failure;
+
+ if (nla_put(skb, TCA_NETEM_JITTER64, sizeof(q->jitter), &q->jitter))
+ goto nla_put_failure;
+
cor.delay_corr = q->delay_cor.rho;
cor.loss_corr = q->loss_cor.rho;
cor.dup_corr = q->dup_cor.rho;