From 22b33429ab93155895854e9518a253680a920493 Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Sat, 5 Nov 2005 21:14:16 +0100 Subject: [PKT_SCHED]: GRED: Use new generic red interface Simplifies code a lot by separating the red algorithm and the queueing logic. We now differentiate between probability marks and forced marks but sum them together again to not break backwards compatibility. This brings GRED back to the level of RED and improves the accuracy of the averge queue length calculations when stab suggests a zero shift. Signed-off-by: Thomas Graf Signed-off-by: Arnaldo Carvalho de Melo --- net/sched/sch_gred.c | 224 +++++++++++++++++++++------------------------------ 1 file changed, 91 insertions(+), 133 deletions(-) (limited to 'net/sched') diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c index ca6cb271493b..a52490c7af3c 100644 --- a/net/sched/sch_gred.c +++ b/net/sched/sch_gred.c @@ -45,6 +45,7 @@ #include #include #include +#include #if 1 /* control */ #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args) @@ -65,32 +66,15 @@ struct gred_sched; struct gred_sched_data { -/* Parameters */ u32 limit; /* HARD maximal queue length */ - u32 qth_min; /* Min average length threshold: A scaled */ - u32 qth_max; /* Max average length threshold: A scaled */ u32 DP; /* the drop pramaters */ - char Wlog; /* log(W) */ - char Plog; /* random number bits */ - u32 Scell_max; - u32 Rmask; u32 bytesin; /* bytes seen on virtualQ so far*/ u32 packetsin; /* packets seen on virtualQ so far*/ u32 backlog; /* bytes on the virtualQ */ - u32 forced; /* packets dropped for exceeding limits */ - u32 early; /* packets dropped as a warning */ - u32 other; /* packets dropped by invoking drop() */ - u32 pdrop; /* packets dropped because we exceeded physical queue limits */ - char Scell_log; - u8 Stab[256]; u8 prio; /* the prio of this vq */ -/* Variables */ - unsigned long qave; /* Average queue length: A scaled */ - int qcount; /* Packets since last random number generation */ - u32 qR; /* Cached random number */ - - psched_time_t qidlestart; /* Start of idle period */ + struct red_parms parms; + struct red_stats stats; }; enum { @@ -159,13 +143,22 @@ static inline int gred_wred_mode_check(struct Qdisc *sch) return 0; } +static inline unsigned int gred_backlog(struct gred_sched *table, + struct gred_sched_data *q, + struct Qdisc *sch) +{ + if (gred_wred_mode(table)) + return sch->qstats.backlog; + else + return q->backlog; +} + static int gred_enqueue(struct sk_buff *skb, struct Qdisc* sch) { - psched_time_t now; struct gred_sched_data *q=NULL; struct gred_sched *t= qdisc_priv(sch); - unsigned long qave=0; + unsigned long qavg = 0; int i=0; if (!t->initd && skb_queue_len(&sch->q) < (sch->dev->tx_queue_len ? : 1)) { @@ -195,8 +188,9 @@ gred_enqueue(struct sk_buff *skb, struct Qdisc* sch) if ((!t->tab[i]) || (i==q->DP)) continue; - if ((t->tab[i]->prio < q->prio) && (PSCHED_IS_PASTPERFECT(t->tab[i]->qidlestart))) - qave +=t->tab[i]->qave; + if (t->tab[i]->prio < q->prio && + !red_is_idling(&t->tab[i]->parms)) + qavg +=t->tab[i]->parms.qavg; } } @@ -205,68 +199,49 @@ gred_enqueue(struct sk_buff *skb, struct Qdisc* sch) q->bytesin+=skb->len; if (gred_wred_mode(t)) { - qave=0; - q->qave=t->tab[t->def]->qave; - q->qidlestart=t->tab[t->def]->qidlestart; + qavg = 0; + q->parms.qavg = t->tab[t->def]->parms.qavg; + q->parms.qidlestart = t->tab[t->def]->parms.qidlestart; } - if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) { - long us_idle; - PSCHED_GET_TIME(now); - us_idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max); - PSCHED_SET_PASTPERFECT(q->qidlestart); + q->parms.qavg = red_calc_qavg(&q->parms, gred_backlog(t, q, sch)); - q->qave >>= q->Stab[(us_idle>>q->Scell_log)&0xFF]; - } else { - if (gred_wred_mode(t)) { - q->qave += sch->qstats.backlog - (q->qave >> q->Wlog); - } else { - q->qave += q->backlog - (q->qave >> q->Wlog); - } - - } - + if (red_is_idling(&q->parms)) + red_end_of_idle_period(&q->parms); if (gred_wred_mode(t)) - t->tab[t->def]->qave=q->qave; + t->tab[t->def]->parms.qavg = q->parms.qavg; - if ((q->qave+qave) < q->qth_min) { - q->qcount = -1; -enqueue: - if (q->backlog + skb->len <= q->limit) { - q->backlog += skb->len; -do_enqueue: - __skb_queue_tail(&sch->q, skb); - sch->qstats.backlog += skb->len; - sch->bstats.bytes += skb->len; - sch->bstats.packets++; - return 0; - } else { - q->pdrop++; - } + switch (red_action(&q->parms, q->parms.qavg + qavg)) { + case RED_DONT_MARK: + break; -drop: - kfree_skb(skb); - sch->qstats.drops++; - return NET_XMIT_DROP; - } - if ((q->qave+qave) >= q->qth_max) { - q->qcount = -1; - sch->qstats.overlimits++; - q->forced++; - goto drop; + case RED_PROB_MARK: + sch->qstats.overlimits++; + q->stats.prob_drop++; + goto drop; + + case RED_HARD_MARK: + sch->qstats.overlimits++; + q->stats.forced_drop++; + goto drop; } - if (++q->qcount) { - if ((((qave+q->qave) - q->qth_min)>>q->Wlog)*q->qcount < q->qR) - goto enqueue; - q->qcount = 0; - q->qR = net_random()&q->Rmask; - sch->qstats.overlimits++; - q->early++; - goto drop; + + if (q->backlog + skb->len <= q->limit) { + q->backlog += skb->len; +do_enqueue: + __skb_queue_tail(&sch->q, skb); + sch->qstats.backlog += skb->len; + sch->bstats.bytes += skb->len; + sch->bstats.packets++; + return 0; } - q->qR = net_random()&q->Rmask; - goto enqueue; + + q->stats.pdrop++; +drop: + kfree_skb(skb); + sch->qstats.drops++; + return NET_XMIT_DROP; } static int @@ -276,7 +251,9 @@ gred_requeue(struct sk_buff *skb, struct Qdisc* sch) struct gred_sched *t= qdisc_priv(sch); q= t->tab[(skb->tc_index&0xf)]; /* error checking here -- probably unnecessary */ - PSCHED_SET_PASTPERFECT(q->qidlestart); + + if (red_is_idling(&q->parms)) + red_end_of_idle_period(&q->parms); __skb_queue_head(&sch->q, skb); sch->qstats.backlog += skb->len; @@ -299,7 +276,7 @@ gred_dequeue(struct Qdisc* sch) if (q) { q->backlog -= skb->len; if (!q->backlog && !gred_wred_mode(t)) - PSCHED_GET_TIME(q->qidlestart); + red_start_of_idle_period(&q->parms); } else { D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); } @@ -312,7 +289,7 @@ gred_dequeue(struct Qdisc* sch) D2PRINTK("no default VQ set: Results will be " "screwed up\n"); else - PSCHED_GET_TIME(q->qidlestart); + red_start_of_idle_period(&q->parms); } return NULL; @@ -333,9 +310,9 @@ static unsigned int gred_drop(struct Qdisc* sch) q= t->tab[(skb->tc_index&0xf)]; if (q) { q->backlog -= len; - q->other++; + q->stats.other++; if (!q->backlog && !gred_wred_mode(t)) - PSCHED_GET_TIME(q->qidlestart); + red_start_of_idle_period(&q->parms); } else { D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); } @@ -350,7 +327,7 @@ static unsigned int gred_drop(struct Qdisc* sch) return 0; } - PSCHED_GET_TIME(q->qidlestart); + red_start_of_idle_period(&q->parms); return 0; } @@ -369,14 +346,12 @@ static void gred_reset(struct Qdisc* sch) q= t->tab[i]; if (!q) continue; - PSCHED_SET_PASTPERFECT(q->qidlestart); - q->qave = 0; - q->qcount = -1; + red_restart(&q->parms); q->backlog = 0; - q->other=0; - q->forced=0; - q->pdrop=0; - q->early=0; + q->stats.other = 0; + q->stats.forced_drop = 0; + q->stats.prob_drop = 0; + q->stats.pdrop = 0; } } @@ -450,25 +425,19 @@ static inline int gred_change_vq(struct Qdisc *sch, int dp, q = table->tab[dp]; q->DP = dp; q->prio = prio; - - q->Wlog = ctl->Wlog; - q->Plog = ctl->Plog; q->limit = ctl->limit; - q->Scell_log = ctl->Scell_log; - q->Rmask = ctl->Plog < 32 ? ((1<Plog) - 1) : ~0UL; - q->Scell_max = (255<Scell_log); - q->qth_min = ctl->qth_min<Wlog; - q->qth_max = ctl->qth_max<Wlog; - q->qave=0; - q->backlog=0; - q->qcount = -1; - q->other=0; - q->forced=0; - q->pdrop=0; - q->early=0; - - PSCHED_SET_PASTPERFECT(q->qidlestart); - memcpy(q->Stab, stab, 256); + + if (q->backlog == 0) + red_end_of_idle_period(&q->parms); + + red_set_parms(&q->parms, + ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog, + ctl->Scell_log, stab); + + q->stats.other = 0; + q->stats.forced_drop = 0; + q->stats.prob_drop = 0; + q->stats.pdrop = 0; return 0; } @@ -592,37 +561,26 @@ static int gred_dump(struct Qdisc *sch, struct sk_buff *skb) opt.DP = q->DP; opt.backlog = q->backlog; opt.prio = q->prio; - opt.qth_min = q->qth_min >> q->Wlog; - opt.qth_max = q->qth_max >> q->Wlog; - opt.Wlog = q->Wlog; - opt.Plog = q->Plog; - opt.Scell_log = q->Scell_log; - opt.other = q->other; - opt.early = q->early; - opt.forced = q->forced; - opt.pdrop = q->pdrop; + opt.qth_min = q->parms.qth_min >> q->parms.Wlog; + opt.qth_max = q->parms.qth_max >> q->parms.Wlog; + opt.Wlog = q->parms.Wlog; + opt.Plog = q->parms.Plog; + opt.Scell_log = q->parms.Scell_log; + opt.other = q->stats.other; + opt.early = q->stats.prob_drop; + opt.forced = q->stats.forced_drop; + opt.pdrop = q->stats.pdrop; opt.packets = q->packetsin; opt.bytesin = q->bytesin; - if (q->qave) { - if (gred_wred_mode(table)) { - q->qidlestart=table->tab[table->def]->qidlestart; - q->qave=table->tab[table->def]->qave; - } - if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) { - long idle; - unsigned long qave; - psched_time_t now; - PSCHED_GET_TIME(now); - idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max); - qave = q->qave >> q->Stab[(idle>>q->Scell_log)&0xFF]; - opt.qave = qave >> q->Wlog; - - } else { - opt.qave = q->qave >> q->Wlog; - } + if (gred_wred_mode(table)) { + q->parms.qidlestart = + table->tab[table->def]->parms.qidlestart; + q->parms.qavg = table->tab[table->def]->parms.qavg; } + opt.qave = red_calc_qavg(&q->parms, q->parms.qavg); + append_opt: RTA_APPEND(skb, sizeof(opt), &opt); } -- cgit v1.2.3