From a73ed26bbae7327370c5bd298f07de78df9e3466 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 9 Dec 2011 02:46:45 +0000 Subject: [PATCH] sch_red: generalize accurate MAX_P support to RED/GRED/CHOKE Now RED uses a Q0.32 number to store max_p (max probability), allow RED/GRED/CHOKE to use/report full resolution at config/dump time. Old tc binaries are non aware of new attributes, and still set/get Plog. New tc binary set/get both Plog and max_p for backward compatibility, they display "probability value" if they get max_p from new kernels. # tc -d qdisc show dev ... ... qdisc red 10: parent 1:1 limit 360Kb min 30Kb max 90Kb ecn ewma 5 probability 0.09 Scell_log 15 Make sure we avoid potential divides by 0 in reciprocal_value(), if (max_th - min_th) is big. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/pkt_sched.h | 2 ++ include/net/red.h | 16 +++++++++++----- net/sched/sch_choke.c | 8 +++++++- net/sched/sch_gred.c | 22 ++++++++++++++++++---- net/sched/sch_red.c | 9 +++++++-- 5 files changed, 45 insertions(+), 12 deletions(-) diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h index e41e0d4de24b..8786ea741f52 100644 --- a/include/linux/pkt_sched.h +++ b/include/linux/pkt_sched.h @@ -216,6 +216,7 @@ enum { TCA_GRED_PARMS, TCA_GRED_STAB, TCA_GRED_DPS, + TCA_GRED_MAX_P, __TCA_GRED_MAX, }; @@ -255,6 +256,7 @@ enum { TCA_CHOKE_UNSPEC, TCA_CHOKE_PARMS, TCA_CHOKE_STAB, + TCA_CHOKE_MAX_P, __TCA_CHOKE_MAX, }; diff --git a/include/net/red.h b/include/net/red.h index 24606b22d01e..ef715a16cce4 100644 --- a/include/net/red.h +++ b/include/net/red.h @@ -155,9 +155,10 @@ static inline u32 red_maxp(u8 Plog) static inline void red_set_parms(struct red_parms *p, u32 qth_min, u32 qth_max, u8 Wlog, u8 Plog, - u8 Scell_log, u8 *stab) + u8 Scell_log, u8 *stab, u32 max_P) { int delta = qth_max - qth_min; + u32 max_p_delta; /* Reset average queue length, the value is strictly bound * to the parameters below, reseting hurts a bit but leaving @@ -173,10 +174,14 @@ static inline void red_set_parms(struct red_parms *p, if (delta < 0) delta = 1; p->qth_delta = delta; - p->max_P = red_maxp(Plog); - p->max_P *= delta; /* max_P = (qth_max-qth_min)/2^Plog */ - - p->max_P_reciprocal = reciprocal_value(p->max_P / delta); + if (!max_P) { + max_P = red_maxp(Plog); + max_P *= delta; /* max_P = (qth_max - qth_min)/2^Plog */ + } + p->max_P = max_P; + max_p_delta = max_P / delta; + max_p_delta = max(max_p_delta, 1U); + p->max_P_reciprocal = reciprocal_value(max_p_delta); /* RED Adaptative target : * [min_th + 0.4*(min_th - max_th), @@ -380,6 +385,7 @@ static inline void red_adaptative_algo(struct red_parms *p) p->max_P = (p->max_P/10)*9; /* maxp = maxp * Beta */ max_p_delta = DIV_ROUND_CLOSEST(p->max_P, p->qth_delta); + max_p_delta = max(max_p_delta, 1U); p->max_P_reciprocal = reciprocal_value(max_p_delta); } #endif diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c index 205d369a217c..bef00acb8bd2 100644 --- a/net/sched/sch_choke.c +++ b/net/sched/sch_choke.c @@ -394,6 +394,7 @@ static void choke_reset(struct Qdisc *sch) static const struct nla_policy choke_policy[TCA_CHOKE_MAX + 1] = { [TCA_CHOKE_PARMS] = { .len = sizeof(struct tc_red_qopt) }, [TCA_CHOKE_STAB] = { .len = RED_STAB_SIZE }, + [TCA_CHOKE_MAX_P] = { .type = NLA_U32 }, }; @@ -415,6 +416,7 @@ static int choke_change(struct Qdisc *sch, struct nlattr *opt) int err; struct sk_buff **old = NULL; unsigned int mask; + u32 max_P; if (opt == NULL) return -EINVAL; @@ -427,6 +429,8 @@ static int choke_change(struct Qdisc *sch, struct nlattr *opt) tb[TCA_CHOKE_STAB] == NULL) return -EINVAL; + max_P = tb[TCA_CHOKE_MAX_P] ? nla_get_u32(tb[TCA_CHOKE_MAX_P]) : 0; + ctl = nla_data(tb[TCA_CHOKE_PARMS]); if (ctl->limit > CHOKE_MAX_QUEUE) @@ -476,7 +480,8 @@ static int choke_change(struct Qdisc *sch, struct nlattr *opt) red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog, ctl->Scell_log, - nla_data(tb[TCA_CHOKE_STAB])); + nla_data(tb[TCA_CHOKE_STAB]), + max_P); if (q->head == q->tail) red_end_of_idle_period(&q->parms); @@ -510,6 +515,7 @@ static int choke_dump(struct Qdisc *sch, struct sk_buff *skb) goto nla_put_failure; NLA_PUT(skb, TCA_CHOKE_PARMS, sizeof(opt), &opt); + NLA_PUT_U32(skb, TCA_CHOKE_MAX_P, q->parms.max_P); return nla_nest_end(skb, opts); nla_put_failure: diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c index b9493a09a870..a1b7407ac2a4 100644 --- a/net/sched/sch_gred.c +++ b/net/sched/sch_gred.c @@ -34,7 +34,7 @@ struct gred_sched; struct gred_sched_data { u32 limit; /* HARD maximal queue length */ - u32 DP; /* the drop pramaters */ + u32 DP; /* the drop parameters */ u32 bytesin; /* bytes seen on virtualQ so far*/ u32 packetsin; /* packets seen on virtualQ so far*/ u32 backlog; /* bytes on the virtualQ */ @@ -379,7 +379,8 @@ static inline int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps) } static inline int gred_change_vq(struct Qdisc *sch, int dp, - struct tc_gred_qopt *ctl, int prio, u8 *stab) + struct tc_gred_qopt *ctl, int prio, + u8 *stab, u32 max_P) { struct gred_sched *table = qdisc_priv(sch); struct gred_sched_data *q; @@ -400,7 +401,7 @@ static inline int gred_change_vq(struct Qdisc *sch, int dp, red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog, - ctl->Scell_log, stab); + ctl->Scell_log, stab, max_P); return 0; } @@ -409,6 +410,7 @@ static const struct nla_policy gred_policy[TCA_GRED_MAX + 1] = { [TCA_GRED_PARMS] = { .len = sizeof(struct tc_gred_qopt) }, [TCA_GRED_STAB] = { .len = 256 }, [TCA_GRED_DPS] = { .len = sizeof(struct tc_gred_sopt) }, + [TCA_GRED_MAX_P] = { .type = NLA_U32 }, }; static int gred_change(struct Qdisc *sch, struct nlattr *opt) @@ -418,6 +420,7 @@ static int gred_change(struct Qdisc *sch, struct nlattr *opt) struct nlattr *tb[TCA_GRED_MAX + 1]; int err, prio = GRED_DEF_PRIO; u8 *stab; + u32 max_P; if (opt == NULL) return -EINVAL; @@ -433,6 +436,8 @@ static int gred_change(struct Qdisc *sch, struct nlattr *opt) tb[TCA_GRED_STAB] == NULL) return -EINVAL; + max_P = tb[TCA_GRED_MAX_P] ? nla_get_u32(tb[TCA_GRED_MAX_P]) : 0; + err = -EINVAL; ctl = nla_data(tb[TCA_GRED_PARMS]); stab = nla_data(tb[TCA_GRED_STAB]); @@ -457,7 +462,7 @@ static int gred_change(struct Qdisc *sch, struct nlattr *opt) sch_tree_lock(sch); - err = gred_change_vq(sch, ctl->DP, ctl, prio, stab); + err = gred_change_vq(sch, ctl->DP, ctl, prio, stab, max_P); if (err < 0) goto errout_locked; @@ -498,6 +503,7 @@ static int gred_dump(struct Qdisc *sch, struct sk_buff *skb) struct gred_sched *table = qdisc_priv(sch); struct nlattr *parms, *opts = NULL; int i; + u32 max_p[MAX_DPs]; struct tc_gred_sopt sopt = { .DPs = table->DPs, .def_DP = table->def, @@ -509,6 +515,14 @@ static int gred_dump(struct Qdisc *sch, struct sk_buff *skb) if (opts == NULL) goto nla_put_failure; NLA_PUT(skb, TCA_GRED_DPS, sizeof(sopt), &sopt); + + for (i = 0; i < MAX_DPs; i++) { + struct gred_sched_data *q = table->tab[i]; + + max_p[i] = q ? q->parms.max_P : 0; + } + NLA_PUT(skb, TCA_GRED_MAX_P, sizeof(max_p), max_p); + parms = nla_nest_start(skb, TCA_GRED_PARMS); if (parms == NULL) goto nla_put_failure; diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c index 8f5a85bf9d10..ce2256a17d7e 100644 --- a/net/sched/sch_red.c +++ b/net/sched/sch_red.c @@ -170,6 +170,7 @@ static void red_destroy(struct Qdisc *sch) static const struct nla_policy red_policy[TCA_RED_MAX + 1] = { [TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) }, [TCA_RED_STAB] = { .len = RED_STAB_SIZE }, + [TCA_RED_MAX_P] = { .type = NLA_U32 }, }; static int red_change(struct Qdisc *sch, struct nlattr *opt) @@ -179,6 +180,7 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt) struct tc_red_qopt *ctl; struct Qdisc *child = NULL; int err; + u32 max_P; if (opt == NULL) return -EINVAL; @@ -191,6 +193,8 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt) tb[TCA_RED_STAB] == NULL) return -EINVAL; + max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0; + ctl = nla_data(tb[TCA_RED_PARMS]); if (ctl->limit > 0) { @@ -209,8 +213,9 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt) } red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog, - ctl->Plog, ctl->Scell_log, - nla_data(tb[TCA_RED_STAB])); + ctl->Plog, ctl->Scell_log, + nla_data(tb[TCA_RED_STAB]), + max_P); del_timer(&q->adapt_timer); if (ctl->flags & TC_RED_ADAPTATIVE) -- 2.30.2