1 files changed, 65 insertions, 22 deletions

diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index 25c171c32715..4ced47bf6089 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -91,16 +91,57 @@ struct gred_sched_data
         psched_time_t   qidlestart;     /* Start of idle period */
 };
 
+enum {
+        GRED_WRED_MODE = 1,
+};
+
 struct gred_sched
 {
         struct gred_sched_data *tab[MAX_DPs];
+        unsigned long   flags;
         u32             DPs;   
         u32             def; 
         u8              initd; 
         u8              grio; 
-        u8              eqp; 
 };
 
+static inline int gred_wred_mode(struct gred_sched *table)
+{
+        return test_bit(GRED_WRED_MODE, &table->flags);
+}
+
+static inline void gred_enable_wred_mode(struct gred_sched *table)
+{
+        __set_bit(GRED_WRED_MODE, &table->flags);
+}
+
+static inline void gred_disable_wred_mode(struct gred_sched *table)
+{
+        __clear_bit(GRED_WRED_MODE, &table->flags);
+}
+
+static inline int gred_wred_mode_check(struct Qdisc *sch)
+{
+        struct gred_sched *table = qdisc_priv(sch);
+        int i;
+
+        /* Really ugly O(n^2) but shouldn't be necessary too frequent. */
+        for (i = 0; i < table->DPs; i++) {
+                struct gred_sched_data *q = table->tab[i];
+                int n;
+
+                if (q == NULL)
+                        continue;
+
+                for (n = 0; n < table->DPs; n++)
+                        if (table->tab[n] && table->tab[n] != q &&
+                            table->tab[n]->prio == q->prio)
+                                return 1;
+        }
+
+        return 0;
+}
+
 static int
 gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
 {
@@ -132,7 +173,7 @@ gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
             "general backlog %d\n",skb->tc_index&0xf,sch->handle,q->backlog,
             sch->qstats.backlog);
         /* sum up all the qaves of prios <= to ours to get the new qave*/
-        if (!t->eqp && t->grio) {
+        if (!gred_wred_mode(t) && t->grio) {
                 for (i=0;i<t->DPs;i++) {
                         if ((!t->tab[i]) || (i==q->DP)) 
                                 continue; 
@@ -146,7 +187,7 @@ gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
         q->packetsin++;
         q->bytesin+=skb->len;
 
-        if (t->eqp && t->grio) {
+        if (gred_wred_mode(t)) {
                 qave=0;
                 q->qave=t->tab[t->def]->qave;
                 q->qidlestart=t->tab[t->def]->qidlestart;
@@ -160,7 +201,7 @@ gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
 
                 q->qave >>= q->Stab[(us_idle>>q->Scell_log)&0xFF];
         } else {
-                if (t->eqp) {
+                if (gred_wred_mode(t)) {
                         q->qave += sch->qstats.backlog - (q->qave >> q->Wlog);
                 } else {
                         q->qave += q->backlog - (q->qave >> q->Wlog);
@@ -169,7 +210,7 @@ gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
         }
         
 
-        if (t->eqp && t->grio) 
+        if (gred_wred_mode(t))
                 t->tab[t->def]->qave=q->qave;
 
         if ((q->qave+qave) < q->qth_min) {
@@ -240,7 +281,7 @@ gred_dequeue(struct Qdisc* sch)
                 q= t->tab[(skb->tc_index&0xf)];
                 if (q) {
                         q->backlog -= skb->len;
-                        if (!q->backlog && !t->eqp)
+                        if (!q->backlog && !gred_wred_mode(t))
                                 PSCHED_GET_TIME(q->qidlestart);
                 } else {
                         D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); 
@@ -248,7 +289,7 @@ gred_dequeue(struct Qdisc* sch)
                 return skb;
         }
 
-        if (t->eqp) {
+        if (gred_wred_mode(t)) {
                         q= t->tab[t->def];
                         if (!q) 
                                 D2PRINTK("no default VQ set: Results will be "
@@ -276,7 +317,7 @@ static unsigned int gred_drop(struct Qdisc* sch)
                 if (q) {
                         q->backlog -= len;
                         q->other++;
-                        if (!q->backlog && !t->eqp)
+                        if (!q->backlog && !gred_wred_mode(t))
                                 PSCHED_GET_TIME(q->qidlestart);
                 } else {
                         D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); 
@@ -330,7 +371,6 @@ static int gred_change(struct Qdisc *sch, struct rtattr *opt)
         struct tc_gred_sopt *sopt;
         struct rtattr *tb[TCA_GRED_STAB];
         struct rtattr *tb2[TCA_GRED_DPS];
-        int i;
 
         if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
                 return -EINVAL;
@@ -344,7 +384,17 @@ static int gred_change(struct Qdisc *sch, struct rtattr *opt)
                 sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
                 table->DPs=sopt->DPs;   
                 table->def=sopt->def_DP; 
-                table->grio=sopt->grio; 
+
+                if (sopt->grio) {
+                        table->grio = 1;
+                        gred_disable_wred_mode(table);
+                        if (gred_wred_mode_check(sch))
+                                gred_enable_wred_mode(table);
+                } else {
+                        table->grio = 0;
+                        gred_disable_wred_mode(table);
+                }
+
                 table->initd=0;
                 /* probably need to clear all the table DP entries as well */
                 return 0;
@@ -413,17 +463,10 @@ static int gred_change(struct Qdisc *sch, struct rtattr *opt)
         PSCHED_SET_PASTPERFECT(q->qidlestart);
         memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
 
-        if ( table->initd && table->grio) {
-        /* this looks ugly but it's not in the fast path */
-                for (i=0;i<table->DPs;i++) {
-                        if ((!table->tab[i]) || (i==q->DP) )    
-                                continue; 
-                        if (table->tab[i]->prio == q->prio ){
-                                /* WRED mode detected */
-                                table->eqp=1;
-                                break;
-                        }
-                }
+        if (table->grio) {
+                gred_disable_wred_mode(table);
+                if (gred_wred_mode_check(sch))
+                        gred_enable_wred_mode(table);
         }
 
         if (!table->initd) {
@@ -541,7 +584,7 @@ static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
                 dst->DP=q->DP;
                 dst->backlog=q->backlog;
                 if (q->qave) {
-                        if (table->eqp && table->grio) {
+                        if (gred_wred_mode(table)) {
                                 q->qidlestart=table->tab[table->def]->qidlestart;
                                 q->qave=table->tab[table->def]->qave;
                         }