[SRU][F:linux-bluefield][PATCH V1 7/7] net/sched: act_police: add support for packet-per-second policing
Bodong Wang
bodong at nvidia.com
Tue Aug 10 20:14:17 UTC 2021
From: Baowen Zheng <baowen.zheng at corigine.com>
BugLink: https://bugs.launchpad.net/bugs/1938818
Allow a policer action to enforce a rate-limit based on packets-per-second,
configurable using a packet-per-second rate and burst parameters.
e.g.
tc filter add dev tap1 parent ffff: u32 match \
u32 0 0 police pkts_rate 3000 pkts_burst 1000
Testing was unable to uncover a performance impact of this change on
existing features.
Signed-off-by: Baowen Zheng <baowen.zheng at corigine.com>
Signed-off-by: Simon Horman <simon.horman at netronome.com>
Signed-off-by: Louis Peens <louis.peens at netronome.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit 2ffe0395288aa237ff7e0143366bd1cd57bfc5b7)
Signed-off-by: Bodong Wang <bodong at nvidia.com>
---
include/net/sch_generic.h | 14 ++++++++
include/net/tc_act/tc_police.h | 48 ++++++++++++++++++++++++---
include/uapi/linux/pkt_cls.h | 2 ++
net/sched/act_police.c | 59 +++++++++++++++++++++++++++++----
net/sched/sch_generic.c | 75 ++++++++++++++++++++++++++++--------------
5 files changed, 162 insertions(+), 36 deletions(-)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index c395d63..76840ed 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -1283,6 +1283,20 @@ static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
}
+struct psched_pktrate {
+ u64 rate_pkts_ps; /* packets per second */
+ u32 mult;
+ u8 shift;
+};
+
+static inline u64 psched_pkt2t_ns(const struct psched_pktrate *r,
+ unsigned int pkt_num)
+{
+ return ((u64)pkt_num * r->mult) >> r->shift;
+}
+
+void psched_ppscfg_precompute(struct psched_pktrate *r, u64 pktrate64);
+
/* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
* The fast path only needs to access filter list and to update stats
*/
diff --git a/include/net/tc_act/tc_police.h b/include/net/tc_act/tc_police.h
index ae117f7..7264951 100644
--- a/include/net/tc_act/tc_police.h
+++ b/include/net/tc_act/tc_police.h
@@ -10,10 +10,13 @@ struct tcf_police_params {
s64 tcfp_burst;
u32 tcfp_mtu;
s64 tcfp_mtu_ptoks;
+ s64 tcfp_pkt_burst;
struct psched_ratecfg rate;
bool rate_present;
struct psched_ratecfg peak;
bool peak_present;
+ struct psched_pktrate ppsrate;
+ bool pps_present;
struct rcu_head rcu;
};
@@ -24,6 +27,7 @@ struct tcf_police {
spinlock_t tcfp_lock ____cacheline_aligned_in_smp;
s64 tcfp_toks;
s64 tcfp_ptoks;
+ s64 tcfp_pkttoks;
s64 tcfp_t_c;
};
@@ -99,14 +103,50 @@ static inline u32 tcf_police_burst(const struct tc_action *act)
static inline u64 tcf_police_rate_pkt_ps(const struct tc_action *act)
{
- /* Not implemented */
- return 0;
+ struct tcf_police *police = to_police(act);
+ struct tcf_police_params *params;
+
+ params = rcu_dereference_protected(police->params,
+ lockdep_is_held(&police->tcf_lock));
+ return params->ppsrate.rate_pkts_ps;
}
static inline u32 tcf_police_burst_pkt(const struct tc_action *act)
{
- /* Not implemented */
- return 0;
+ struct tcf_police *police = to_police(act);
+ struct tcf_police_params *params;
+ u32 burst;
+
+ params = rcu_dereference_protected(police->params,
+ lockdep_is_held(&police->tcf_lock));
+
+ /*
+ * "rate" pkts "burst" nanoseconds
+ * ------------ * -------------------
+ * 1 second 2^6 ticks
+ *
+ * ------------------------------------
+ * NSEC_PER_SEC nanoseconds
+ * ------------------------
+ * 2^6 ticks
+ *
+ * "rate" pkts "burst" nanoseconds 2^6 ticks
+ * = ------------ * ------------------- * ------------------------
+ * 1 second 2^6 ticks NSEC_PER_SEC nanoseconds
+ *
+ * "rate" * "burst"
+ * = ---------------- pkts/nanosecond
+ * NSEC_PER_SEC^2
+ *
+ *
+ * "rate" * "burst"
+ * = ---------------- pkts/second
+ * NSEC_PER_SEC
+ */
+ burst = div_u64(params->tcfp_pkt_burst * params->ppsrate.rate_pkts_ps,
+ NSEC_PER_SEC);
+
+ return burst;
}
static inline u32 tcf_police_tcfp_mtu(const struct tc_action *act)
diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index b4b0568..624dfe2 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h
@@ -167,6 +167,8 @@ enum {
TCA_POLICE_PAD,
TCA_POLICE_RATE64,
TCA_POLICE_PEAKRATE64,
+ TCA_POLICE_PKTRATE64,
+ TCA_POLICE_PKTBURST64,
__TCA_POLICE_MAX
#define TCA_POLICE_RESULT TCA_POLICE_RESULT
};
diff --git a/net/sched/act_police.c b/net/sched/act_police.c
index 817880c..207f8ef 100644
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -42,6 +42,8 @@ static int tcf_police_walker(struct net *net, struct sk_buff *skb,
[TCA_POLICE_RESULT] = { .type = NLA_U32 },
[TCA_POLICE_RATE64] = { .type = NLA_U64 },
[TCA_POLICE_PEAKRATE64] = { .type = NLA_U64 },
+ [TCA_POLICE_PKTRATE64] = { .type = NLA_U64, .min = 1 },
+ [TCA_POLICE_PKTBURST64] = { .type = NLA_U64, .min = 1 },
};
static int tcf_police_init(struct net *net, struct nlattr *nla,
@@ -61,6 +63,7 @@ static int tcf_police_init(struct net *net, struct nlattr *nla,
bool exists = false;
u32 index;
u64 rate64, prate64;
+ u64 pps, ppsburst;
if (nla == NULL)
return -EINVAL;
@@ -142,6 +145,21 @@ static int tcf_police_init(struct net *net, struct nlattr *nla,
}
}
+ if ((tb[TCA_POLICE_PKTRATE64] && !tb[TCA_POLICE_PKTBURST64]) ||
+ (!tb[TCA_POLICE_PKTRATE64] && tb[TCA_POLICE_PKTBURST64])) {
+ NL_SET_ERR_MSG(extack,
+ "Both or neither packet-per-second burst and rate must be provided");
+ err = -EINVAL;
+ goto failure;
+ }
+
+ if (tb[TCA_POLICE_PKTRATE64] && R_tab) {
+ NL_SET_ERR_MSG(extack,
+ "packet-per-second and byte-per-second rate limits not allowed in same action");
+ err = -EINVAL;
+ goto failure;
+ }
+
new = kzalloc(sizeof(*new), GFP_KERNEL);
if (unlikely(!new)) {
err = -ENOMEM;
@@ -183,6 +201,14 @@ static int tcf_police_init(struct net *net, struct nlattr *nla,
if (tb[TCA_POLICE_AVRATE])
new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
+ if (tb[TCA_POLICE_PKTRATE64]) {
+ pps = nla_get_u64(tb[TCA_POLICE_PKTRATE64]);
+ ppsburst = nla_get_u64(tb[TCA_POLICE_PKTBURST64]);
+ new->pps_present = true;
+ new->tcfp_pkt_burst = PSCHED_TICKS2NS(ppsburst);
+ psched_ppscfg_precompute(&new->ppsrate, pps);
+ }
+
spin_lock_bh(&police->tcf_lock);
spin_lock_bh(&police->tcfp_lock);
police->tcfp_t_c = ktime_get_ns();
@@ -217,8 +243,8 @@ static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_police *police = to_police(a);
+ s64 now, toks, ppstoks = 0, ptoks = 0;
struct tcf_police_params *p;
- s64 now, toks, ptoks = 0;
int ret;
tcf_lastuse_update(&police->tcf_tm);
@@ -236,7 +262,7 @@ static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
}
if (qdisc_pkt_len(skb) <= p->tcfp_mtu) {
- if (!p->rate_present) {
+ if (!p->rate_present && !p->pps_present) {
ret = p->tcfp_result;
goto end;
}
@@ -251,14 +277,23 @@ static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
ptoks -= (s64)psched_l2t_ns(&p->peak,
qdisc_pkt_len(skb));
}
- toks += police->tcfp_toks;
- if (toks > p->tcfp_burst)
- toks = p->tcfp_burst;
- toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb));
- if ((toks|ptoks) >= 0) {
+ if (p->rate_present) {
+ toks += police->tcfp_toks;
+ if (toks > p->tcfp_burst)
+ toks = p->tcfp_burst;
+ toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb));
+ } else if (p->pps_present) {
+ ppstoks = min_t(s64, now - police->tcfp_t_c, p->tcfp_pkt_burst);
+ ppstoks += police->tcfp_pkttoks;
+ if (ppstoks > p->tcfp_pkt_burst)
+ ppstoks = p->tcfp_pkt_burst;
+ ppstoks -= (s64)psched_pkt2t_ns(&p->ppsrate, 1);
+ }
+ if ((toks | ptoks | ppstoks) >= 0) {
police->tcfp_t_c = now;
police->tcfp_toks = toks;
police->tcfp_ptoks = ptoks;
+ police->tcfp_pkttoks = ppstoks;
spin_unlock_bh(&police->tcfp_lock);
ret = p->tcfp_result;
goto inc_drops;
@@ -331,6 +366,16 @@ static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a,
TCA_POLICE_PAD))
goto nla_put_failure;
}
+ if (p->pps_present) {
+ if (nla_put_u64_64bit(skb, TCA_POLICE_PKTRATE64,
+ police->params->ppsrate.rate_pkts_ps,
+ TCA_POLICE_PAD))
+ goto nla_put_failure;
+ if (nla_put_u64_64bit(skb, TCA_POLICE_PKTBURST64,
+ PSCHED_NS2TICKS(p->tcfp_pkt_burst),
+ TCA_POLICE_PAD))
+ goto nla_put_failure;
+ }
if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
goto nla_put_failure;
if (p->tcfp_result &&
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 399e578..05155ea 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1381,6 +1381,48 @@ void dev_shutdown(struct net_device *dev)
WARN_ON(timer_pending(&dev->watchdog_timer));
}
+/**
+ * psched_ratecfg_precompute__() - Pre-compute values for reciprocal division
+ * @rate: Rate to compute reciprocal division values of
+ * @mult: Multiplier for reciprocal division
+ * @shift: Shift for reciprocal division
+ *
+ * The multiplier and shift for reciprocal division by rate are stored
+ * in mult and shift.
+ *
+ * The deal here is to replace a divide by a reciprocal one
+ * in fast path (a reciprocal divide is a multiply and a shift)
+ *
+ * Normal formula would be :
+ * time_in_ns = (NSEC_PER_SEC * len) / rate_bps
+ *
+ * We compute mult/shift to use instead :
+ * time_in_ns = (len * mult) >> shift;
+ *
+ * We try to get the highest possible mult value for accuracy,
+ * but have to make sure no overflows will ever happen.
+ *
+ * reciprocal_value() is not used here it doesn't handle 64-bit values.
+ */
+static void psched_ratecfg_precompute__(u64 rate, u32 *mult, u8 *shift)
+{
+ u64 factor = NSEC_PER_SEC;
+
+ *mult = 1;
+ *shift = 0;
+
+ if (rate <= 0)
+ return;
+
+ for (;;) {
+ *mult = div64_u64(factor, rate);
+ if (*mult & (1U << 31) || factor & (1ULL << 63))
+ break;
+ factor <<= 1;
+ (*shift)++;
+ }
+}
+
void psched_ratecfg_precompute(struct psched_ratecfg *r,
const struct tc_ratespec *conf,
u64 rate64)
@@ -1389,34 +1431,17 @@ void psched_ratecfg_precompute(struct psched_ratecfg *r,
r->overhead = conf->overhead;
r->rate_bytes_ps = max_t(u64, conf->rate, rate64);
r->linklayer = (conf->linklayer & TC_LINKLAYER_MASK);
- r->mult = 1;
- /*
- * The deal here is to replace a divide by a reciprocal one
- * in fast path (a reciprocal divide is a multiply and a shift)
- *
- * Normal formula would be :
- * time_in_ns = (NSEC_PER_SEC * len) / rate_bps
- *
- * We compute mult/shift to use instead :
- * time_in_ns = (len * mult) >> shift;
- *
- * We try to get the highest possible mult value for accuracy,
- * but have to make sure no overflows will ever happen.
- */
- if (r->rate_bytes_ps > 0) {
- u64 factor = NSEC_PER_SEC;
-
- for (;;) {
- r->mult = div64_u64(factor, r->rate_bytes_ps);
- if (r->mult & (1U << 31) || factor & (1ULL << 63))
- break;
- factor <<= 1;
- r->shift++;
- }
- }
+ psched_ratecfg_precompute__(r->rate_bytes_ps, &r->mult, &r->shift);
}
EXPORT_SYMBOL(psched_ratecfg_precompute);
+void psched_ppscfg_precompute(struct psched_pktrate *r, u64 pktrate64)
+{
+ r->rate_pkts_ps = pktrate64;
+ psched_ratecfg_precompute__(r->rate_pkts_ps, &r->mult, &r->shift);
+}
+EXPORT_SYMBOL(psched_ppscfg_precompute);
+
static void mini_qdisc_rcu_func(struct rcu_head *head)
{
}
--
1.8.3.1
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