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>

3 files changed, 62 insertions, 52 deletions

diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c
index bef00acb8bd2..e465064d39a3 100644
--- 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 53204de71c39..0b15236be7b6 100644
--- 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 ce2256a17d7e..a5cc3012cf42 100644
--- 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);
 }