[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 <tgraf@suug.ch>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index ca6cb27..a52490c 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -45,6 +45,7 @@
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
+#include <net/red.h>
#if 1 /* control */
#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
@@ -65,32 +66,15 @@
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 @@
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 @@
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 @@
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;
+ switch (red_action(&q->parms, q->parms.qavg + qavg)) {
+ case RED_DONT_MARK:
+ break;
+
+ 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->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++;
- }
+ __skb_queue_tail(&sch->q, skb);
+ sch->qstats.backlog += skb->len;
+ sch->bstats.bytes += skb->len;
+ sch->bstats.packets++;
+ return 0;
+ }
+ q->stats.pdrop++;
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;
- }
- 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;
- }
- q->qR = net_random()&q->Rmask;
- goto enqueue;
+ kfree_skb(skb);
+ sch->qstats.drops++;
+ return NET_XMIT_DROP;
}
static int
@@ -276,7 +251,9 @@
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 @@
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 @@
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 @@
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 @@
return 0;
}
- PSCHED_GET_TIME(q->qidlestart);
+ red_start_of_idle_period(&q->parms);
return 0;
}
@@ -369,14 +346,12 @@
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 @@
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<<ctl->Plog) - 1) : ~0UL;
- q->Scell_max = (255<<q->Scell_log);
- q->qth_min = ctl->qth_min<<ctl->Wlog;
- q->qth_max = ctl->qth_max<<ctl->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 @@
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);
}