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Commit eeca6688 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

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: default avatarEric Dumazet <eric.dumazet@gmail.com>
CC: Dave Taht <dave.taht@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 18cb8098

include/net/red.h

+55 −43
Original line number Diff line number Diff line
@@ -137,7 +137,9 @@ struct red_parms { 
	u8		Wlog;		/* log(W)		*/

	u8		Plog;		/* random number bits	*/

	u8		Stab[RED_STAB_SIZE];

};



struct red_vars {

	/* Variables */

	int		qcount;		/* Number of packets since last random

					   number generation */
@@ -152,6 +154,16 @@ static inline u32 red_maxp(u8 Plog) 
	return Plog < 32 ? (~0U >> Plog) : ~0U;

}



static inline void red_set_vars(struct red_vars *v)

{

	/* Reset average queue length, the value is strictly bound

	 * to the parameters below, reseting hurts a bit but leaving

	 * it might result in an unreasonable qavg for a while. --TGR

	 */

	v->qavg		= 0;



	v->qcount	= -1;

}



static inline void red_set_parms(struct red_parms *p,

				 u32 qth_min, u32 qth_max, u8 Wlog, u8 Plog,
@@ -160,13 +172,6 @@ static inline void red_set_parms(struct red_parms *p, 
	int delta = qth_max - qth_min;

	u32 max_p_delta;



	/* Reset average queue length, the value is strictly bound

	 * to the parameters below, reseting hurts a bit but leaving

	 * it might result in an unreasonable qavg for a while. --TGR

	 */

	p->qavg		= 0;



	p->qcount	= -1;

	p->qth_min	= qth_min << Wlog;

	p->qth_max	= qth_max << Wlog;

	p->Wlog		= Wlog;
@@ -197,31 +202,32 @@ static inline void red_set_parms(struct red_parms *p, 
	memcpy(p->Stab, stab, sizeof(p->Stab));

}



static inline int red_is_idling(const struct red_parms *p)

static inline int red_is_idling(const struct red_vars *v)

{

	return p->qidlestart.tv64 != 0;

	return v->qidlestart.tv64 != 0;

}



static inline void red_start_of_idle_period(struct red_parms *p)

static inline void red_start_of_idle_period(struct red_vars *v)

{

	p->qidlestart = ktime_get();

	v->qidlestart = ktime_get();

}



static inline void red_end_of_idle_period(struct red_parms *p)

static inline void red_end_of_idle_period(struct red_vars *v)

{

	p->qidlestart.tv64 = 0;

	v->qidlestart.tv64 = 0;

}



static inline void red_restart(struct red_parms *p)

static inline void red_restart(struct red_vars *v)

{

	red_end_of_idle_period(p);

	p->qavg = 0;

	p->qcount = -1;

	red_end_of_idle_period(v);

	v->qavg = 0;

	v->qcount = -1;

}



static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms *p)

static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms *p,

							 const struct red_vars *v)

{

	s64 delta = ktime_us_delta(ktime_get(), p->qidlestart);

	s64 delta = ktime_us_delta(ktime_get(), v->qidlestart);

	long us_idle = min_t(s64, delta, p->Scell_max);

	int  shift;
@@ -248,7 +254,7 @@ static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms 
	shift = p->Stab[(us_idle >> p->Scell_log) & RED_STAB_MASK];



	if (shift)

		return p->qavg >> shift;

		return v->qavg >> shift;

	else {

		/* Approximate initial part of exponent with linear function:

		 *
@@ -257,16 +263,17 @@ static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms 
		 * Seems, it is the best solution to

		 * problem of too coarse exponent tabulation.

		 */

		us_idle = (p->qavg * (u64)us_idle) >> p->Scell_log;

		us_idle = (v->qavg * (u64)us_idle) >> p->Scell_log;



		if (us_idle < (p->qavg >> 1))

			return p->qavg - us_idle;

		if (us_idle < (v->qavg >> 1))

			return v->qavg - us_idle;

		else

			return p->qavg >> 1;

			return v->qavg >> 1;

	}

}



static inline unsigned long red_calc_qavg_no_idle_time(const struct red_parms *p,

						       const struct red_vars *v,

						       unsigned int backlog)

{

	/*
@@ -278,16 +285,17 @@ static inline unsigned long red_calc_qavg_no_idle_time(const struct red_parms *p 
	 *

	 * --ANK (980924)

	 */

	return p->qavg + (backlog - (p->qavg >> p->Wlog));

	return v->qavg + (backlog - (v->qavg >> p->Wlog));

}



static inline unsigned long red_calc_qavg(const struct red_parms *p,

					  const struct red_vars *v,

					  unsigned int backlog)

{

	if (!red_is_idling(p))

		return red_calc_qavg_no_idle_time(p, backlog);

	if (!red_is_idling(v))

		return red_calc_qavg_no_idle_time(p, v, backlog);

	else

		return red_calc_qavg_from_idle_time(p);

		return red_calc_qavg_from_idle_time(p, v);

}
@@ -296,7 +304,9 @@ static inline u32 red_random(const struct red_parms *p) 
	return reciprocal_divide(net_random(), p->max_P_reciprocal);

}



static inline int red_mark_probability(const struct red_parms *p, unsigned long qavg)

static inline int red_mark_probability(const struct red_parms *p,

				       const struct red_vars *v,

				       unsigned long qavg)

{

	/* The formula used below causes questions.
@@ -314,7 +324,7 @@ static inline int red_mark_probability(const struct red_parms *p, unsigned long 


	   Any questions? --ANK (980924)

	 */

	return !(((qavg - p->qth_min) >> p->Wlog) * p->qcount < p->qR);

	return !(((qavg - p->qth_min) >> p->Wlog) * v->qcount < v->qR);

}



enum {
@@ -323,7 +333,7 @@ enum { 
	RED_ABOVE_MAX_TRESH,

};



static inline int red_cmp_thresh(struct red_parms *p, unsigned long qavg)

static inline int red_cmp_thresh(const struct red_parms *p, unsigned long qavg)

{

	if (qavg < p->qth_min)

		return RED_BELOW_MIN_THRESH;
@@ -339,27 +349,29 @@ enum { 
	RED_HARD_MARK,

};



static inline int red_action(struct red_parms *p, unsigned long qavg)

static inline int red_action(const struct red_parms *p,

			     struct red_vars *v,

			     unsigned long qavg)

{

	switch (red_cmp_thresh(p, qavg)) {

		case RED_BELOW_MIN_THRESH:

			p->qcount = -1;

			v->qcount = -1;

			return RED_DONT_MARK;



		case RED_BETWEEN_TRESH:

			if (++p->qcount) {

				if (red_mark_probability(p, qavg)) {

					p->qcount = 0;

					p->qR = red_random(p);

			if (++v->qcount) {

				if (red_mark_probability(p, v, qavg)) {

					v->qcount = 0;

					v->qR = red_random(p);

					return RED_PROB_MARK;

				}

			} else

				p->qR = red_random(p);

				v->qR = red_random(p);



			return RED_DONT_MARK;



		case RED_ABOVE_MAX_TRESH:

			p->qcount = -1;

			v->qcount = -1;

			return RED_HARD_MARK;

	}
@@ -367,14 +379,14 @@ static inline int red_action(struct red_parms *p, unsigned long qavg) 
	return RED_DONT_MARK;

}



static inline void red_adaptative_algo(struct red_parms *p)

static inline void red_adaptative_algo(struct red_parms *p, struct red_vars *v)

{

	unsigned long qavg;

	u32 max_p_delta;



	qavg = p->qavg;

	if (red_is_idling(p))

		qavg = red_calc_qavg_from_idle_time(p);

	qavg = v->qavg;

	if (red_is_idling(v))

		qavg = red_calc_qavg_from_idle_time(p, v);



	/* p->qavg is fixed point number with point at Wlog */

	qavg >>= p->Wlog;

net/sched/sch_choke.c

+21 −19
Original line number Diff line number Diff line
@@ -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);

net/sched/sch_gred.c

+24 −21
Original line number Diff line number Diff line
@@ -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)

net/sched/sch_red.c

+17 −12
Original line number Diff line number Diff line
@@ -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);

}