net_sched: red: split red_parms into parms and vars

This patch splits the red_parms structure into two components.

One holding the RED 'constant' parameters, and one containing the
variables.

This permits a size reduction of GRED qdisc, and is a preliminary step
to add an optional RED unit to SFQ.

SFQRED will have a single red_parms structure shared by all flows, and a
private red_vars per flow.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Dave Taht <dave.taht@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/red.h b/include/net/red.h
index ef715a1..baab385 100644 (file)
--- a/include/net/red.h
+++ b/include/net/red.h
@@ -137,7 +137,9 @@ struct red_parms {
        u8              Wlog;           /* log(W)               */
        u8              Plog;           /* random number bits   */
        u8              Stab[RED_STAB_SIZE];
+};
 
+struct red_vars {
        /* Variables */
        int             qcount;         /* Number of packets since last random
                                           number generation */
@@ -152,6 +154,16 @@ static inline u32 red_maxp(u8 Plog)
        return Plog < 32 ? (~0U >> Plog) : ~0U;
 }
 
+static inline void red_set_vars(struct red_vars *v)
+{
+       /* Reset average queue length, the value is strictly bound
+        * to the parameters below, reseting hurts a bit but leaving
+        * it might result in an unreasonable qavg for a while. --TGR
+        */
+       v->qavg         = 0;
+
+       v->qcount       = -1;
+}
 
 static inline void red_set_parms(struct red_parms *p,
                                 u32 qth_min, u32 qth_max, u8 Wlog, u8 Plog,
@@ -160,13 +172,6 @@ static inline void red_set_parms(struct red_parms *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
-        * it might result in an unreasonable qavg for a while. --TGR
-        */
-       p->qavg         = 0;
-
-       p->qcount       = -1;
        p->qth_min      = qth_min << Wlog;
        p->qth_max      = qth_max << Wlog;
        p->Wlog         = Wlog;
@@ -197,31 +202,32 @@ static inline void red_set_parms(struct red_parms *p,
        memcpy(p->Stab, stab, sizeof(p->Stab));
 }
 
-static inline int red_is_idling(const struct red_parms *p)
+static inline int red_is_idling(const struct red_vars *v)
 {
-       return p->qidlestart.tv64 != 0;
+       return v->qidlestart.tv64 != 0;
 }
 
-static inline void red_start_of_idle_period(struct red_parms *p)
+static inline void red_start_of_idle_period(struct red_vars *v)
 {
-       p->qidlestart = ktime_get();
+       v->qidlestart = ktime_get();
 }
 
-static inline void red_end_of_idle_period(struct red_parms *p)
+static inline void red_end_of_idle_period(struct red_vars *v)
 {
-       p->qidlestart.tv64 = 0;
+       v->qidlestart.tv64 = 0;
 }
 
-static inline void red_restart(struct red_parms *p)
+static inline void red_restart(struct red_vars *v)
 {
-       red_end_of_idle_period(p);
-       p->qavg = 0;
-       p->qcount = -1;
+       red_end_of_idle_period(v);
+       v->qavg = 0;
+       v->qcount = -1;
 }
 
-static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms *p)
+static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms *p,
+                                                        const struct red_vars *v)
 {
-       s64 delta = ktime_us_delta(ktime_get(), p->qidlestart);
+       s64 delta = ktime_us_delta(ktime_get(), v->qidlestart);
        long us_idle = min_t(s64, delta, p->Scell_max);
        int  shift;
 
@@ -248,7 +254,7 @@ static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms
        shift = p->Stab[(us_idle >> p->Scell_log) & RED_STAB_MASK];
 
        if (shift)
-               return p->qavg >> shift;
+               return v->qavg >> shift;
        else {
                /* Approximate initial part of exponent with linear function:
                 *
@@ -257,16 +263,17 @@ static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms
                 * Seems, it is the best solution to
                 * problem of too coarse exponent tabulation.
                 */
-               us_idle = (p->qavg * (u64)us_idle) >> p->Scell_log;
+               us_idle = (v->qavg * (u64)us_idle) >> p->Scell_log;
 
-               if (us_idle < (p->qavg >> 1))
-                       return p->qavg - us_idle;
+               if (us_idle < (v->qavg >> 1))
+                       return v->qavg - us_idle;
                else
-                       return p->qavg >> 1;
+                       return v->qavg >> 1;
        }
 }
 
 static inline unsigned long red_calc_qavg_no_idle_time(const struct red_parms *p,
+                                                      const struct red_vars *v,
                                                       unsigned int backlog)
 {
        /*
@@ -278,16 +285,17 @@ static inline unsigned long red_calc_qavg_no_idle_time(const struct red_parms *p
         *
         * --ANK (980924)
         */
-       return p->qavg + (backlog - (p->qavg >> p->Wlog));
+       return v->qavg + (backlog - (v->qavg >> p->Wlog));
 }
 
 static inline unsigned long red_calc_qavg(const struct red_parms *p,
+                                         const struct red_vars *v,
                                          unsigned int backlog)
 {
-       if (!red_is_idling(p))
-               return red_calc_qavg_no_idle_time(p, backlog);
+       if (!red_is_idling(v))
+               return red_calc_qavg_no_idle_time(p, v, backlog);
        else
-               return red_calc_qavg_from_idle_time(p);
+               return red_calc_qavg_from_idle_time(p, v);
 }
 
 
@@ -296,7 +304,9 @@ static inline u32 red_random(const struct red_parms *p)
        return reciprocal_divide(net_random(), p->max_P_reciprocal);
 }
 
-static inline int red_mark_probability(const struct red_parms *p, unsigned long qavg)
+static inline int red_mark_probability(const struct red_parms *p,
+                                      const struct red_vars *v,
+                                      unsigned long qavg)
 {
        /* The formula used below causes questions.
 
@@ -314,7 +324,7 @@ static inline int red_mark_probability(const struct red_parms *p, unsigned long
 
           Any questions? --ANK (980924)
         */
-       return !(((qavg - p->qth_min) >> p->Wlog) * p->qcount < p->qR);
+       return !(((qavg - p->qth_min) >> p->Wlog) * v->qcount < v->qR);
 }
 
 enum {
@@ -323,7 +333,7 @@ enum {
        RED_ABOVE_MAX_TRESH,
 };
 
-static inline int red_cmp_thresh(struct red_parms *p, unsigned long qavg)
+static inline int red_cmp_thresh(const struct red_parms *p, unsigned long qavg)
 {
        if (qavg < p->qth_min)
                return RED_BELOW_MIN_THRESH;
@@ -339,27 +349,29 @@ enum {
        RED_HARD_MARK,
 };
 
-static inline int red_action(struct red_parms *p, unsigned long qavg)
+static inline int red_action(const struct red_parms *p,
+                            struct red_vars *v,
+                            unsigned long qavg)
 {
        switch (red_cmp_thresh(p, qavg)) {
                case RED_BELOW_MIN_THRESH:
-                       p->qcount = -1;
+                       v->qcount = -1;
                        return RED_DONT_MARK;
 
                case RED_BETWEEN_TRESH:
-                       if (++p->qcount) {
-                               if (red_mark_probability(p, qavg)) {
-                                       p->qcount = 0;
-                                       p->qR = red_random(p);
+                       if (++v->qcount) {
+                               if (red_mark_probability(p, v, qavg)) {
+                                       v->qcount = 0;
+                                       v->qR = red_random(p);
                                        return RED_PROB_MARK;
                                }
                        } else
-                               p->qR = red_random(p);
+                               v->qR = red_random(p);
 
                        return RED_DONT_MARK;
 
                case RED_ABOVE_MAX_TRESH:
-                       p->qcount = -1;
+                       v->qcount = -1;
                        return RED_HARD_MARK;
        }
 
@@ -367,14 +379,14 @@ static inline int red_action(struct red_parms *p, unsigned long qavg)
        return RED_DONT_MARK;
 }
 
-static inline void red_adaptative_algo(struct red_parms *p)
+static inline void red_adaptative_algo(struct red_parms *p, struct red_vars *v)
 {
        unsigned long qavg;
        u32 max_p_delta;
 
-       qavg = p->qavg;
-       if (red_is_idling(p))
-               qavg = red_calc_qavg_from_idle_time(p);
+       qavg = v->qavg;
+       if (red_is_idling(v))
+               qavg = red_calc_qavg_from_idle_time(p, v);
 
        /* p->qavg is fixed point number with point at Wlog */
        qavg >>= p->Wlog;

diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c
index bef00ac..e465064 100644 (file)
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -57,6 +57,7 @@ struct choke_sched_data {
        struct red_parms parms;
 
 /* Variables */
+       struct red_vars  vars;
        struct tcf_proto *filter_list;
        struct {
                u32     prob_drop;      /* Early probability drops */
@@ -265,7 +266,7 @@ static bool choke_match_random(const struct choke_sched_data *q,
 static int choke_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 {
        struct choke_sched_data *q = qdisc_priv(sch);
-       struct red_parms *p = &q->parms;
+       const struct red_parms *p = &q->parms;
        int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 
        if (q->filter_list) {
@@ -276,13 +277,13 @@ static int choke_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 
        choke_skb_cb(skb)->keys_valid = 0;
        /* Compute average queue usage (see RED) */
-       p->qavg = red_calc_qavg(p, sch->q.qlen);
-       if (red_is_idling(p))
-               red_end_of_idle_period(p);
+       q->vars.qavg = red_calc_qavg(p, &q->vars, sch->q.qlen);
+       if (red_is_idling(&q->vars))
+               red_end_of_idle_period(&q->vars);
 
        /* Is queue small? */
-       if (p->qavg <= p->qth_min)
-               p->qcount = -1;
+       if (q->vars.qavg <= p->qth_min)
+               q->vars.qcount = -1;
        else {
                unsigned int idx;
 
@@ -294,8 +295,8 @@ static int choke_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                }
 
                /* Queue is large, always mark/drop */
-               if (p->qavg > p->qth_max) {
-                       p->qcount = -1;
+               if (q->vars.qavg > p->qth_max) {
+                       q->vars.qcount = -1;
 
                        sch->qstats.overlimits++;
                        if (use_harddrop(q) || !use_ecn(q) ||
@@ -305,10 +306,10 @@ static int choke_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                        }
 
                        q->stats.forced_mark++;
-               } else if (++p->qcount) {
-                       if (red_mark_probability(p, p->qavg)) {
-                               p->qcount = 0;
-                               p->qR = red_random(p);
+               } else if (++q->vars.qcount) {
+                       if (red_mark_probability(p, &q->vars, q->vars.qavg)) {
+                               q->vars.qcount = 0;
+                               q->vars.qR = red_random(p);
 
                                sch->qstats.overlimits++;
                                if (!use_ecn(q) || !INET_ECN_set_ce(skb)) {
@@ -319,7 +320,7 @@ static int choke_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                                q->stats.prob_mark++;
                        }
                } else
-                       p->qR = red_random(p);
+                       q->vars.qR = red_random(p);
        }
 
        /* Admit new packet */
@@ -353,8 +354,8 @@ static struct sk_buff *choke_dequeue(struct Qdisc *sch)
        struct sk_buff *skb;
 
        if (q->head == q->tail) {
-               if (!red_is_idling(&q->parms))
-                       red_start_of_idle_period(&q->parms);
+               if (!red_is_idling(&q->vars))
+                       red_start_of_idle_period(&q->vars);
                return NULL;
        }
 
@@ -377,8 +378,8 @@ static unsigned int choke_drop(struct Qdisc *sch)
        if (len > 0)
                q->stats.other++;
        else {
-               if (!red_is_idling(&q->parms))
-                       red_start_of_idle_period(&q->parms);
+               if (!red_is_idling(&q->vars))
+                       red_start_of_idle_period(&q->vars);
        }
 
        return len;
@@ -388,7 +389,7 @@ static void choke_reset(struct Qdisc *sch)
 {
        struct choke_sched_data *q = qdisc_priv(sch);
 
-       red_restart(&q->parms);
+       red_restart(&q->vars);
 }
 
 static const struct nla_policy choke_policy[TCA_CHOKE_MAX + 1] = {
@@ -482,9 +483,10 @@ static int choke_change(struct Qdisc *sch, struct nlattr *opt)
                      ctl->Plog, ctl->Scell_log,
                      nla_data(tb[TCA_CHOKE_STAB]),
                      max_P);
+       red_set_vars(&q->vars);
 
        if (q->head == q->tail)
-               red_end_of_idle_period(&q->parms);
+               red_end_of_idle_period(&q->vars);
 
        sch_tree_unlock(sch);
        choke_free(old);

diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index 53204de..0b15236 100644 (file)
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -41,6 +41,7 @@ struct gred_sched_data {
        u8              prio;           /* the prio of this vq */
 
        struct red_parms parms;
+       struct red_vars  vars;
        struct red_stats stats;
 };
 
@@ -55,7 +56,7 @@ struct gred_sched {
        u32             red_flags;
        u32             DPs;
        u32             def;
-       struct red_parms wred_set;
+       struct red_vars wred_set;
 };
 
 static inline int gred_wred_mode(struct gred_sched *table)
@@ -125,17 +126,17 @@ static inline u16 tc_index_to_dp(struct sk_buff *skb)
        return skb->tc_index & GRED_VQ_MASK;
 }
 
-static inline void gred_load_wred_set(struct gred_sched *table,
+static inline void gred_load_wred_set(const struct gred_sched *table,
                                      struct gred_sched_data *q)
 {
-       q->parms.qavg = table->wred_set.qavg;
-       q->parms.qidlestart = table->wred_set.qidlestart;
+       q->vars.qavg = table->wred_set.qavg;
+       q->vars.qidlestart = table->wred_set.qidlestart;
 }
 
 static inline void gred_store_wred_set(struct gred_sched *table,
                                       struct gred_sched_data *q)
 {
-       table->wred_set.qavg = q->parms.qavg;
+       table->wred_set.qavg = q->vars.qavg;
 }
 
 static inline int gred_use_ecn(struct gred_sched *t)
@@ -170,7 +171,7 @@ static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                                goto drop;
                }
 
-               /* fix tc_index? --could be controvesial but needed for
+               /* fix tc_index? --could be controversial but needed for
                   requeueing */
                skb->tc_index = (skb->tc_index & ~GRED_VQ_MASK) | dp;
        }
@@ -181,8 +182,8 @@ static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 
                for (i = 0; i < t->DPs; i++) {
                        if (t->tab[i] && t->tab[i]->prio < q->prio &&
-                           !red_is_idling(&t->tab[i]->parms))
-                               qavg += t->tab[i]->parms.qavg;
+                           !red_is_idling(&t->tab[i]->vars))
+                               qavg += t->tab[i]->vars.qavg;
                }
 
        }
@@ -193,15 +194,17 @@ static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch)
        if (gred_wred_mode(t))
                gred_load_wred_set(t, q);
 
-       q->parms.qavg = red_calc_qavg(&q->parms, gred_backlog(t, q, sch));
+       q->vars.qavg = red_calc_qavg(&q->parms,
+                                    &q->vars,
+                                    gred_backlog(t, q, sch));
 
-       if (red_is_idling(&q->parms))
-               red_end_of_idle_period(&q->parms);
+       if (red_is_idling(&q->vars))
+               red_end_of_idle_period(&q->vars);
 
        if (gred_wred_mode(t))
                gred_store_wred_set(t, q);
 
-       switch (red_action(&q->parms, q->parms.qavg + qavg)) {
+       switch (red_action(&q->parms, &q->vars, q->vars.qavg + qavg)) {
        case RED_DONT_MARK:
                break;
 
@@ -260,7 +263,7 @@ static struct sk_buff *gred_dequeue(struct Qdisc *sch)
                        q->backlog -= qdisc_pkt_len(skb);
 
                        if (!q->backlog && !gred_wred_mode(t))
-                               red_start_of_idle_period(&q->parms);
+                               red_start_of_idle_period(&q->vars);
                }
 
                return skb;
@@ -293,7 +296,7 @@ static unsigned int gred_drop(struct Qdisc *sch)
                        q->stats.other++;
 
                        if (!q->backlog && !gred_wred_mode(t))
-                               red_start_of_idle_period(&q->parms);
+                               red_start_of_idle_period(&q->vars);
                }
 
                qdisc_drop(skb, sch);
@@ -320,7 +323,7 @@ static void gred_reset(struct Qdisc *sch)
                if (!q)
                        continue;
 
-               red_restart(&q->parms);
+               red_restart(&q->vars);
                q->backlog = 0;
        }
 }
@@ -398,12 +401,12 @@ static inline int gred_change_vq(struct Qdisc *sch, int dp,
        q->limit = ctl->limit;
 
        if (q->backlog == 0)
-               red_end_of_idle_period(&q->parms);
+               red_end_of_idle_period(&q->vars);
 
        red_set_parms(&q->parms,
                      ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog,
                      ctl->Scell_log, stab, max_P);
-
+       red_set_vars(&q->vars);
        return 0;
 }
 
@@ -563,12 +566,12 @@ static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
                opt.bytesin     = q->bytesin;
 
                if (gred_wred_mode(table)) {
-                       q->parms.qidlestart =
-                               table->tab[table->def]->parms.qidlestart;
-                       q->parms.qavg = table->tab[table->def]->parms.qavg;
+                       q->vars.qidlestart =
+                               table->tab[table->def]->vars.qidlestart;
+                       q->vars.qavg = table->tab[table->def]->vars.qavg;
                }
 
-               opt.qave = red_calc_qavg(&q->parms, q->parms.qavg);
+               opt.qave = red_calc_qavg(&q->parms, &q->vars, q->vars.qavg);
 
 append_opt:
                if (nla_append(skb, sizeof(opt), &opt) < 0)

diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index ce2256a..a5cc301 100644 (file)
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -41,6 +41,7 @@ struct red_sched_data {
        unsigned char           flags;
        struct timer_list       adapt_timer;
        struct red_parms        parms;
+       struct red_vars         vars;
        struct red_stats        stats;
        struct Qdisc            *qdisc;
 };
@@ -61,12 +62,14 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch)
        struct Qdisc *child = q->qdisc;
        int ret;
 
-       q->parms.qavg = red_calc_qavg(&q->parms, child->qstats.backlog);
+       q->vars.qavg = red_calc_qavg(&q->parms,
+                                    &q->vars,
+                                    child->qstats.backlog);
 
-       if (red_is_idling(&q->parms))
-               red_end_of_idle_period(&q->parms);
+       if (red_is_idling(&q->vars))
+               red_end_of_idle_period(&q->vars);
 
-       switch (red_action(&q->parms, q->parms.qavg)) {
+       switch (red_action(&q->parms, &q->vars, q->vars.qavg)) {
        case RED_DONT_MARK:
                break;
 
@@ -117,8 +120,8 @@ static struct sk_buff *red_dequeue(struct Qdisc *sch)
                qdisc_bstats_update(sch, skb);
                sch->q.qlen--;
        } else {
-               if (!red_is_idling(&q->parms))
-                       red_start_of_idle_period(&q->parms);
+               if (!red_is_idling(&q->vars))
+                       red_start_of_idle_period(&q->vars);
        }
        return skb;
 }
@@ -144,8 +147,8 @@ static unsigned int red_drop(struct Qdisc *sch)
                return len;
        }
 
-       if (!red_is_idling(&q->parms))
-               red_start_of_idle_period(&q->parms);
+       if (!red_is_idling(&q->vars))
+               red_start_of_idle_period(&q->vars);
 
        return 0;
 }
@@ -156,7 +159,7 @@ static void red_reset(struct Qdisc *sch)
 
        qdisc_reset(q->qdisc);
        sch->q.qlen = 0;
-       red_restart(&q->parms);
+       red_restart(&q->vars);
 }
 
 static void red_destroy(struct Qdisc *sch)
@@ -212,17 +215,19 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt)
                q->qdisc = child;
        }
 
-       red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog,
+       red_set_parms(&q->parms,
+                     ctl->qth_min, ctl->qth_max, ctl->Wlog,
                      ctl->Plog, ctl->Scell_log,
                      nla_data(tb[TCA_RED_STAB]),
                      max_P);
+       red_set_vars(&q->vars);
 
        del_timer(&q->adapt_timer);
        if (ctl->flags & TC_RED_ADAPTATIVE)
                mod_timer(&q->adapt_timer, jiffies + HZ/2);
 
        if (!q->qdisc->q.qlen)
-               red_start_of_idle_period(&q->parms);
+               red_start_of_idle_period(&q->vars);
 
        sch_tree_unlock(sch);
        return 0;
@@ -235,7 +240,7 @@ static inline void red_adaptative_timer(unsigned long arg)
        spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
 
        spin_lock(root_lock);
-       red_adaptative_algo(&q->parms);
+       red_adaptative_algo(&q->parms, &q->vars);
        mod_timer(&q->adapt_timer, jiffies + HZ/2);
        spin_unlock(root_lock);
 }