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>

1 files changed, 24 insertions, 21 deletions

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)