cregit-Linux how code gets into the kernel

Release 4.11 net/sched/sch_cbq.c

Directory: net/sched
/*
 * net/sched/sch_cbq.c  Class-Based Queueing discipline.
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 *
 * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>


/*      Class-Based Queueing (CBQ) algorithm.
        =======================================

        Sources: [1] Sally Floyd and Van Jacobson, "Link-sharing and Resource
                 Management Models for Packet Networks",
                 IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995

                 [2] Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995

                 [3] Sally Floyd, "Notes on Class-Based Queueing: Setting
                 Parameters", 1996

                 [4] Sally Floyd and Michael Speer, "Experimental Results
                 for Class-Based Queueing", 1998, not published.

        -----------------------------------------------------------------------

        Algorithm skeleton was taken from NS simulator cbq.cc.
        If someone wants to check this code against the LBL version,
        he should take into account that ONLY the skeleton was borrowed,
        the implementation is different. Particularly:

        --- The WRR algorithm is different. Our version looks more
        reasonable (I hope) and works when quanta are allowed to be
        less than MTU, which is always the case when real time classes
        have small rates. Note, that the statement of [3] is
        incomplete, delay may actually be estimated even if class
        per-round allotment is less than MTU. Namely, if per-round
        allotment is W*r_i, and r_1+...+r_k = r < 1

        delay_i <= ([MTU/(W*r_i)]*W*r + W*r + k*MTU)/B

        In the worst case we have IntServ estimate with D = W*r+k*MTU
        and C = MTU*r. The proof (if correct at all) is trivial.


        --- It seems that cbq-2.0 is not very accurate. At least, I cannot
        interpret some places, which look like wrong translations
        from NS. Anyone is advised to find these differences
        and explain to me, why I am wrong 8).

        --- Linux has no EOI event, so that we cannot estimate true class
        idle time. Workaround is to consider the next dequeue event
        as sign that previous packet is finished. This is wrong because of
        internal device queueing, but on a permanently loaded link it is true.
        Moreover, combined with clock integrator, this scheme looks
        very close to an ideal solution.  */

struct cbq_sched_data;



struct cbq_class {
	
struct Qdisc_class_common common;
	
struct cbq_class	*next_alive;	/* next class with backlog in this priority band */

/* Parameters */
	
unsigned char		priority;	/* class priority */
	
unsigned char		priority2;	/* priority to be used after overlimit */
	
unsigned char		ewma_log;	/* time constant for idle time calculation */

	
u32			defmap;

	/* Link-sharing scheduler parameters */
	
long			maxidle;	/* Class parameters: see below. */
	
long			offtime;
	
long			minidle;
	
u32			avpkt;
	
struct qdisc_rate_table	*R_tab;

	/* General scheduler (WRR) parameters */
	
long			allot;
	
long			quantum;	/* Allotment per WRR round */
	
long			weight;		/* Relative allotment: see below */

	
struct Qdisc		*qdisc;		/* Ptr to CBQ discipline */
	
struct cbq_class	*split;		/* Ptr to split node */
	
struct cbq_class	*share;		/* Ptr to LS parent in the class tree */
	
struct cbq_class	*tparent;	/* Ptr to tree parent in the class tree */
	
struct cbq_class	*borrow;	/* NULL if class is bandwidth limited;
                                                   parent otherwise */
	
struct cbq_class	*sibling;	/* Sibling chain */
	
struct cbq_class	*children;	/* Pointer to children chain */

	
struct Qdisc		*q;		/* Elementary queueing discipline */


/* Variables */
	
unsigned char		cpriority;	/* Effective priority */
	
unsigned char		delayed;
	
unsigned char		level;		/* level of the class in hierarchy:
                                                   0 for leaf classes, and maximal
                                                   level of children + 1 for nodes.
                                                 */

	
psched_time_t		last;		/* Last end of service */
	
psched_time_t		undertime;
	
long			avgidle;
	
long			deficit;	/* Saved deficit for WRR */
	
psched_time_t		penalized;
	
struct gnet_stats_basic_packed bstats;
	
struct gnet_stats_queue qstats;
	
struct net_rate_estimator __rcu *rate_est;
	
struct tc_cbq_xstats	xstats;

	
struct tcf_proto __rcu	*filter_list;

	
int			refcnt;
	
int			filters;

	
struct cbq_class	*defaults[TC_PRIO_MAX + 1];
};


struct cbq_sched_data {
	
struct Qdisc_class_hash	clhash;			/* Hash table of all classes */
	
int			nclasses[TC_CBQ_MAXPRIO + 1];
	
unsigned int		quanta[TC_CBQ_MAXPRIO + 1];

	
struct cbq_class	link;

	
unsigned int		activemask;
	
struct cbq_class	*active[TC_CBQ_MAXPRIO + 1];	/* List of all classes
                                                                   with backlog */

#ifdef CONFIG_NET_CLS_ACT
	
struct cbq_class	*rx_class;
#endif
	
struct cbq_class	*tx_class;
	
struct cbq_class	*tx_borrowed;
	
int			tx_len;
	
psched_time_t		now;		/* Cached timestamp */
	
unsigned int		pmask;

	
struct hrtimer		delay_timer;
	
struct qdisc_watchdog	watchdog;	/* Watchdog timer,
                                                   started when CBQ has
                                                   backlog, but cannot
                                                   transmit just now */
	
psched_tdiff_t		wd_expires;
	
int			toplevel;
	
u32			hgenerator;
};



#define L2T(cl, len)	qdisc_l2t((cl)->R_tab, len)



static inline struct cbq_class *

cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
{
	struct Qdisc_class_common *clc;

	clc = qdisc_class_find(&q->clhash, classid);
	if (clc == NULL)
		return NULL;
	return container_of(clc, struct cbq_class, common);
}


Contributors
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Patrick McHardy2037.04%125.00%


Eric Dumazet1833.33%125.00%


Linus Torvalds (pre-git)1629.63%250.00%


Total54100.00%4100.00%



#ifdef CONFIG_NET_CLS_ACT



static struct cbq_class *

cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
{
	struct cbq_class *cl;

	for (cl = this->tparent; cl; cl = cl->tparent) {
		struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT];

		if (new != NULL && new != this)
			return new;
	}
	return NULL;
}


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Eric Dumazet1115.94%133.33%


Total69100.00%3100.00%



#endif

/* Classify packet. The procedure is pretty complicated, but
 * it allows us to combine link sharing and priority scheduling
 * transparently.
 *
 * Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
 * so that it resolves to split nodes. Then packets are classified
 * by logical priority, or a more specific classifier may be attached
 * to the split node.
 */



static struct cbq_class *

cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *head = &q->link;
	struct cbq_class **defmap;
	struct cbq_class *cl = NULL;
	u32 prio = skb->priority;
	struct tcf_proto *fl;
	struct tcf_result res;

	/*
         *  Step 1. If skb->priority points to one of our classes, use it.
         */
	if (TC_H_MAJ(prio ^ sch->handle) == 0 &&
	    (cl = cbq_class_lookup(q, prio)) != NULL)
		return cl;

	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
	for (;;) {
		int result = 0;
		defmap = head->defaults;

		fl = rcu_dereference_bh(head->filter_list);
		/*
                 * Step 2+n. Apply classifier.
                 */
		result = tc_classify(skb, fl, &res, true);
		if (!fl || result < 0)
			goto fallback;

		cl = (void *)res.class;
		if (!cl) {
			if (TC_H_MAJ(res.classid))
				cl = cbq_class_lookup(q, res.classid);
			else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL)
				cl = defmap[TC_PRIO_BESTEFFORT];

			if (cl == NULL)
				goto fallback;
		}
		if (cl->level >= head->level)
			goto fallback;
#ifdef CONFIG_NET_CLS_ACT
		switch (result) {
		case TC_ACT_QUEUED:
		case TC_ACT_STOLEN:
			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
		case TC_ACT_SHOT:
			return NULL;
		case TC_ACT_RECLASSIFY:
			return cbq_reclassify(skb, cl);
		}
#endif
		if (cl->level == 0)
			return cl;

		/*
                 * Step 3+n. If classifier selected a link sharing class,
                 *         apply agency specific classifier.
                 *         Repeat this procdure until we hit a leaf node.
                 */
		head = cl;
	}

fallback:
	cl = head;

	/*
         * Step 4. No success...
         */
	if (TC_H_MAJ(prio) == 0 &&
	    !(cl = head->defaults[prio & TC_PRIO_MAX]) &&
	    !(cl = head->defaults[TC_PRIO_BESTEFFORT]))
		return head;

	return cl;
}


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Linus Torvalds (pre-git)26575.50%428.57%


Jamal Hadi Salim236.55%17.14%


Patrick McHardy205.70%214.29%


John Fastabend205.70%17.14%


Eric Dumazet123.42%214.29%


Jarek Poplawski51.42%214.29%


Daniel Borkmann30.85%17.14%


Stephen Hemminger30.85%17.14%


Total351100.00%14100.00%



/*
 * A packet has just been enqueued on the empty class.
 * cbq_activate_class adds it to the tail of active class list
 * of its priority band.
 */




static inline void cbq_activate_class(struct cbq_class *cl)
{
	struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
	int prio = cl->cpriority;
	struct cbq_class *cl_tail;

	cl_tail = q->active[prio];
	q->active[prio] = cl;

	if (cl_tail != NULL) {
		cl->next_alive = cl_tail->next_alive;
		cl_tail->next_alive = cl;
	} else {
		cl->next_alive = cl;
		q->activemask |= (1<<prio);
	}
}


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Linus Torvalds (pre-git)9195.79%250.00%


Stephen Hemminger33.16%125.00%


Eric Dumazet11.05%125.00%


Total95100.00%4100.00%



/*
 * Unlink class from active chain.
 * Note that this same procedure is done directly in cbq_dequeue*
 * during round-robin procedure.
 */




static void cbq_deactivate_class(struct cbq_class *this)
{
	struct cbq_sched_data *q = qdisc_priv(this->qdisc);
	int prio = this->cpriority;
	struct cbq_class *cl;
	struct cbq_class *cl_prev = q->active[prio];

	do {
		cl = cl_prev->next_alive;
		if (cl == this) {
			cl_prev->next_alive = cl->next_alive;
			cl->next_alive = NULL;

			if (cl == q->active[prio]) {
				q->active[prio] = cl_prev;
				if (cl == q->active[prio]) {
					q->active[prio] = NULL;
					q->activemask &= ~(1<<prio);
					return;
				}
			}
			return;
		}
	} while ((cl_prev = cl) != q->active[prio]);
}


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Linus Torvalds (pre-git)14898.01%266.67%


Stephen Hemminger31.99%133.33%


Total151100.00%3100.00%





static void

cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
{
	int toplevel = q->toplevel;

	if (toplevel > cl->level) {
		psched_time_t now = psched_get_time();

		do {
			if (cl->undertime < now) {
				q->toplevel = cl->level;
				return;
			}
		} while ((cl = cl->borrow) != NULL && toplevel > cl->level);
	}
}


Contributors
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Linus Torvalds (pre-git)7593.75%350.00%


Patrick McHardy33.75%233.33%


Vasily Averin22.50%116.67%


Total80100.00%6100.00%





static int

cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
	    struct sk_buff **to_free)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	int uninitialized_var(ret);
	struct cbq_class *cl = cbq_classify(skb, sch, &ret);

#ifdef CONFIG_NET_CLS_ACT
	q->rx_class = cl;
#endif
	if (cl == NULL) {
		if (ret & __NET_XMIT_BYPASS)
			qdisc_qstats_drop(sch);
		__qdisc_drop(skb, to_free);
		return ret;
	}

	ret = qdisc_enqueue(skb, cl->q, to_free);
	if (ret == NET_XMIT_SUCCESS) {
		sch->q.qlen++;
		cbq_mark_toplevel(q, cl);
		if (!cl->next_alive)
			cbq_activate_class(cl);
		return ret;
	}

	if (net_xmit_drop_count(ret)) {
		qdisc_qstats_drop(sch);
		cbq_mark_toplevel(q, cl);
		cl->qstats.drops++;
	}
	return ret;
}


Contributors
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Linus Torvalds (pre-git)9252.87%425.00%


Jamal Hadi Salim2313.22%16.25%


Patrick McHardy1910.92%318.75%


Jarek Poplawski116.32%212.50%


Eric Dumazet116.32%16.25%


John Fastabend63.45%16.25%


Jussi Kivilinna52.87%16.25%


Stephen Hemminger31.72%16.25%


Satyam Sharma31.72%16.25%


Thomas Graf10.57%16.25%


Total174100.00%16100.00%



/* Overlimit action: penalize leaf class by adding offtime */



static void cbq_overlimit(struct cbq_class *cl)
{
	struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
	psched_tdiff_t delay = cl->undertime - q->now;

	if (!cl->delayed) {
		delay += cl->offtime;

		/*
                 * Class goes to sleep, so that it will have no
                 * chance to work avgidle. Let's forgive it 8)
                 *
                 * BTW cbq-2.0 has a crap in this
                 * place, apparently they forgot to shift it by cl->ewma_log.
                 */
		if (cl->avgidle < 0)
			delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
		if (cl->avgidle < cl->minidle)
			cl->avgidle = cl->minidle;
		if (delay <= 0)
			delay = 1;
		cl->undertime = q->now + delay;

		cl->xstats.overactions++;
		cl->delayed = 1;
	}
	if (q->wd_expires == 0 || q->wd_expires > delay)
		q->wd_expires = delay;

	/* Dirty work! We must schedule wakeups based on
         * real available rate, rather than leaf rate,
         * which may be tiny (even zero).
         */
	if (q->toplevel == TC_CBQ_MAXLEVEL) {
		struct cbq_class *b;
		psched_tdiff_t base_delay = q->wd_expires;

		for (b = cl->borrow; b; b = b->borrow) {
			delay = b->undertime - q->now;
			if (delay < base_delay) {
				if (delay <= 0)
					delay = 1;
				base_delay = delay;
			}
		}

		q->wd_expires = base_delay;
	}
}


Contributors
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Linus Torvalds (pre-git)12253.04%342.86%


Florian Westphal10344.78%114.29%


Stephen Hemminger31.30%114.29%


Patrick McHardy10.43%114.29%


Eric Dumazet10.43%114.29%


Total230100.00%7100.00%






static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
				       psched_time_t now)
{
	struct cbq_class *cl;
	struct cbq_class *cl_prev = q->active[prio];
	psched_time_t sched = now;

	if (cl_prev == NULL)
		return 0;

	do {
		cl = cl_prev->next_alive;
		if (now - cl->penalized > 0) {
			cl_prev->next_alive = cl->next_alive;
			cl->next_alive = NULL;
			cl->cpriority = cl->priority;
			cl->delayed = 0;
			cbq_activate_class(cl);

			if (cl == q->active[prio]) {
				q->active[prio] = cl_prev;
				if (cl == q->active[prio]) {
					q->active[prio] = NULL;
					return 0;
				}
			}

			cl = cl_prev->next_alive;
		} else if (sched - cl->penalized > 0)
			sched = cl->penalized;
	} while ((cl_prev = cl) != q->active[prio]);

	return sched - now;
}


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Linus Torvalds (pre-git)18796.89%250.00%


Patrick McHardy63.11%250.00%


Total193100.00%4100.00%






static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
{
	struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data,
						delay_timer);
	struct Qdisc *sch = q->watchdog.qdisc;
	psched_time_t now;
	psched_tdiff_t delay = 0;
	unsigned int pmask;

	now = psched_get_time();

	pmask = q->pmask;
	q->pmask = 0;

	while (pmask) {
		int prio = ffz(~pmask);
		psched_tdiff_t tmp;

		pmask &= ~(1<<prio);

		tmp = cbq_undelay_prio(q, prio, now);
		if (tmp > 0) {
			q->pmask |= 1<<prio;
			if (tmp < delay || delay == 0)
				delay = tmp;
		}
	}

	if (delay) {
		ktime_t time;

		time = 0;
		time = ktime_add_ns(time, PSCHED_TICKS2NS(now + delay));
		hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS_PINNED);
	}

	__netif_schedule(qdisc_root(sch));
	return HRTIMER_NORESTART;
}


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Linus Torvalds (pre-git)11964.32%218.18%


Patrick McHardy5730.81%218.18%


David S. Miller63.24%436.36%


Eric Dumazet21.08%218.18%


Jarek Poplawski10.54%19.09%


Total185100.00%11100.00%



/*
 * It is mission critical procedure.
 *
 * We "regenerate" toplevel cutoff, if transmitting class
 * has backlog and it is not regulated. It is not part of
 * original CBQ description, but looks more reasonable.
 * Probably, it is wrong. This question needs further investigation.
 */



static inline void

cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl,
		    struct cbq_class *borrowed)
{
	if (cl && q->toplevel >= borrowed->level) {
		if (cl->q->q.qlen > 1) {
			do {
				if (borrowed->undertime == PSCHED_PASTPERFECT) {
					q->toplevel = borrowed->level;
					return;
				}
			} while ((borrowed = borrowed->borrow) != NULL);
		}
#if 0
	/* It is not necessary now. Uncommenting it
           will save CPU cycles, but decrease fairness.
         */
		q->toplevel = TC_CBQ_MAXLEVEL;
#endif
	}
}


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Patrick McHardy22.17%125.00%


Eric Dumazet11.09%125.00%


Total92100.00%4100.00%





static void

cbq_update(struct cbq_sched_data *q)
{
	struct cbq_class *this = q->tx_class;
	struct cbq_class *cl = this;
	int len = q->tx_len;
	psched_time_t now;

	q->tx_class = NULL;
	/* Time integrator. We calculate EOS time
         * by adding expected packet transmission time.
         */
	now = q->now + L2T(&q->link, len);

	for ( ; cl; cl = cl->share) {
		long avgidle = cl->avgidle;
		long idle;

		cl->bstats.packets++;
		cl->bstats.bytes += len;

		/*
                 * (now - last) is total time between packet right edges.
                 * (last_pktlen/rate) is "virtual" busy time, so that
                 *
                 *      idle = (now - last) - last_pktlen/rate
                 */

		idle = now - cl->last;
		if ((unsigned long)idle > 128*1024*1024) {
			avgidle = cl->maxidle;
		} else {
			idle -= L2T(cl, len);

		/* true_avgidle := (1-W)*true_avgidle + W*idle,
                 * where W=2^{-ewma_log}. But cl->avgidle is scaled:
                 * cl->avgidle == true_avgidle/W,
                 * hence:
                 */
			avgidle += idle - (avgidle>>cl->ewma_log);
		}

		if (avgidle <= 0) {
			/* Overlimit or at-limit */

			if (avgidle < cl->minidle)
				avgidle = cl->minidle;

			cl->avgidle = avgidle;

			/* Calculate expected time, when this class
                         * will be allowed to send.
                         * It will occur, when:
                         * (1-W)*true_avgidle + W*delay = 0, i.e.
                         * idle = (1/W - 1)*(-true_avgidle)
                         * or
                         * idle = (1 - W)*(-cl->avgidle);
                         */
			idle = (-avgidle) - ((-avgidle) >> cl->ewma_log);

			/*
                         * That is not all.
                         * To maintain the rate allocated to the class,
                         * we add to undertime virtual clock,
                         * necessary to complete transmitted packet.
                         * (len/phys_bandwidth has been already passed
                         * to the moment of cbq_update)
                         */

			idle -= L2T(&q->link, len);
			idle += L2T(cl, len);

			cl->undertime = now + idle;
		} else {
			/* Underlimit */

			cl->undertime = PSCHED_PASTPERFECT;
			if (avgidle > cl->maxidle)
				cl->avgidle = cl->maxidle;
			else
				cl->avgidle = avgidle;
		}
		if ((s64)(now - cl->last) > 0)
			cl->last = now;
	}

	cbq_update_toplevel(q, this, q->tx_borrowed);
}


Contributors
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Linus Torvalds (pre-git)24883.50%333.33%


Vasily Averin3511.78%111.11%


Patrick McHardy82.69%333.33%


Eric Dumazet41.35%111.11%


Thomas Graf20.67%111.11%


Total297100.00%9100.00%





static inline struct cbq_class *

cbq_under_limit(struct cbq_class *cl)
{
	struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
	struct cbq_class *this_cl = cl;

	if (cl->tparent == NULL)
		return cl;

	if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) {
		cl->delayed = 0;
		return cl;
	}

	do {
		/* It is very suspicious place. Now overlimit
                 * action is generated for not bounded classes
                 * only if link is completely congested.
                 * Though it is in agree with ancestor-only paradigm,
                 * it looks very stupid. Particularly,
                 * it means that this chunk of code will either
                 * never be called or result in strong amplification
                 * of burstiness. Dangerous, silly, and, however,
                 * no another solution exists.
                 */
		cl = cl->borrow;
		if (!cl) {
			this_cl->qstats.overlimits++;
			cbq_overlimit(this_cl);
			return NULL;
		}
		if (cl->level > q->toplevel)
			return NULL;
	} while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime);

	cl->delayed = 0;
	return cl;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10674.65%225.00%


Eric Dumazet2517.61%112.50%


Patrick McHardy64.23%225.00%


Stephen Hemminger32.11%112.50%


Florian Westphal10.70%112.50%


Thomas Graf10.70%112.50%


Total142100.00%8100.00%





static inline struct sk_buff *

cbq_dequeue_prio(struct Qdisc *sch, int prio)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *cl_tail, *cl_prev, *cl;
	struct sk_buff *skb;
	int deficit;

	cl_tail = cl_prev = q->active[prio];
	cl = cl_prev->next_alive;

	do {
		deficit = 0;

		/* Start round */
		do {
			struct cbq_class *borrow = cl;

			if (cl->q->q.qlen &&
			    (borrow = cbq_under_limit(cl)) == NULL)
				goto skip_class;

			if (cl->deficit <= 0) {
				/* Class exhausted its allotment per
                                 * this round. Switch to the next one.
                                 */
				deficit = 1;
				cl->deficit += cl->quantum;
				goto next_class;
			}

			skb = cl->q->dequeue(cl->q);

			/* Class did not give us any skb :-(
                         * It could occur even if cl->q->q.qlen != 0
                         * f.e. if cl->q == "tbf"
                         */
			if (skb == NULL)
				goto skip_class;

			cl->deficit -= qdisc_pkt_len(skb);
			q->tx_class = cl;
			q->tx_borrowed = borrow;
			if (borrow != cl) {
#ifndef CBQ_XSTATS_BORROWS_BYTES
				borrow->xstats.borrows++;
				cl->xstats.borrows++;
#else
				borrow->xstats.borrows += qdisc_pkt_len(skb);
				cl->xstats.borrows += qdisc_pkt_len(skb);
#endif
			}
			q->tx_len = qdisc_pkt_len(skb);

			if (cl->deficit <= 0) {
				q->active[prio] = cl;
				cl = cl->next_alive;
				cl->deficit += cl->quantum;
			}
			return skb;

skip_class:
			if (cl->q->q.qlen == 0 || prio != cl->cpriority) {
				/* Class is empty or penalized.
                                 * Unlink it from active chain.
                                 */
				cl_prev->next_alive = cl->next_alive;
				cl->next_alive = NULL;

				/* Did cl_tail point to it? */
				if (cl == cl_tail) {
					/* Repair it! */
					cl_tail = cl_prev;

					/* Was it the last class in this band? */
					if (cl == cl_tail) {
						/* Kill the band! */
						q->active[prio] = NULL;
						q->activemask &= ~(1<<prio);
						if (cl->q->q.qlen)
							cbq_activate_class(cl);
						return NULL;
					}

					q->active[prio] = cl_tail;
				}
				if (cl->q->q.qlen)
					cbq_activate_class(cl);

				cl = cl_prev;
			}

next_class:
			cl_prev = cl;
			cl = cl->next_alive;
		} while (cl_prev != cl_tail);
	} while (deficit);

	q->active[prio] = cl_prev;

	return NULL;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)41495.39%350.00%


Jussi Kivilinna122.76%116.67%


Eric Dumazet51.15%116.67%


Stephen Hemminger30.69%116.67%


Total434100.00%6100.00%





static inline struct sk_buff *

cbq_dequeue_1(struct Qdisc *sch)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct sk_buff *skb;
	unsigned int activemask;

	activemask = q->activemask & 0xFF;
	while (activemask) {
		int prio = ffz(~activemask);
		activemask &= ~(1<<prio);
		skb = cbq_dequeue_prio(sch, prio);
		if (skb)
			return skb;
	}
	return NULL;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6071.43%133.33%


Eric Dumazet2125.00%133.33%


Stephen Hemminger33.57%133.33%


Total84100.00%3100.00%





static struct sk_buff *

cbq_dequeue(struct Qdisc *sch)
{
	struct sk_buff *skb;
	struct cbq_sched_data *q = qdisc_priv(sch);
	psched_time_t now;

	now = psched_get_time();

	if (q->tx_class)
		cbq_update(q);

	q->now = now;

	for (;;) {
		q->wd_expires = 0;

		skb = cbq_dequeue_1(sch);
		if (skb) {
			qdisc_bstats_update(sch, skb);
			sch->q.qlen--;
			return skb;
		}

		/* All the classes are overlimit.
                 *
                 * It is possible, if:
                 *
                 * 1. Scheduler is empty.
                 * 2. Toplevel cutoff inhibited borrowing.
                 * 3. Root class is overlimit.
                 *
                 * Reset 2d and 3d conditions and retry.
                 *
                 * Note, that NS and cbq-2.0 are buggy, peeking
                 * an arbitrary class is appropriate for ancestor-only
                 * sharing, but not for toplevel algorithm.
                 *
                 * Our version is better, but slower, because it requires
                 * two passes, but it is unavoidable with top-level sharing.
                 */

		if (q->toplevel == TC_CBQ_MAXLEVEL &&
		    q->link.undertime == PSCHED_PASTPERFECT)
			break;

		q->toplevel = TC_CBQ_MAXLEVEL;
		q->link.undertime = PSCHED_PASTPERFECT;
	}

	/* No packets in scheduler or nobody wants to give them to us :-(
         * Sigh... start watchdog timer in the last case.
         */

	if (sch->q.qlen) {
		qdisc_qstats_overlimit(sch);
		if (q->wd_expires)
			qdisc_watchdog_schedule(&q->watchdog,
						now + q->wd_expires);
	}
	return NULL;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)12977.25%218.18%


Patrick McHardy137.78%327.27%


Eric Dumazet105.99%218.18%


Vasily Averin63.59%19.09%


John Fastabend31.80%19.09%


Stephen Hemminger31.80%19.09%


Vinay K. Nallamothu31.80%19.09%


Total167100.00%11100.00%



/* CBQ class maintanance routines */




static void cbq_adjust_levels(struct cbq_class *this)
{
	if (this == NULL)
		return;

	do {
		int level = 0;
		struct cbq_class *cl;

		cl = this->children;
		if (cl) {
			do {
				if (cl->level > level)
					level = cl->level;
			} while ((cl = cl->sibling) != this->children);
		}
		this->level = level + 1;
	} while ((this = this->tparent) != NULL);
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)9295.83%150.00%


Eric Dumazet44.17%150.00%


Total96100.00%2100.00%






static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio)
{
	struct cbq_class *cl;
	unsigned int h;

	if (q->quanta[prio] == 0)
		return;

	for (h = 0; h < q->clhash.hashsize; h++) {
		hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
			/* BUGGGG... Beware! This expression suffer of
                         * arithmetic overflows!
                         */
			if (cl->priority == prio) {
				cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/
					q->quanta[prio];
			}
			if (cl->quantum <= 0 ||
			    cl->quantum > 32*qdisc_dev(cl->qdisc)->mtu) {
				pr_warn("CBQ: class %08x has bad quantum==%ld, repaired.\n",
					cl->common.classid, cl->quantum);
				cl->quantum = qdisc_dev(cl->qdisc)->mtu/2 + 1;
			}
		}
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13685.00%233.33%


Patrick McHardy1610.00%116.67%


David S. Miller63.75%116.67%


Eric Dumazet10.62%116.67%


Yang Yingliang10.62%116.67%


Total160100.00%6100.00%






static void cbq_sync_defmap(struct cbq_class *cl)
{
	struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
	struct cbq_class *split = cl->split;
	unsigned int h;
	int i;

	if (split == NULL)
		return;

	for (i = 0; i <= TC_PRIO_MAX; i++) {
		if (split->defaults[i] == cl && !(cl->defmap & (1<<i)))
			split->defaults[i] = NULL;
	}

	for (i = 0; i <= TC_PRIO_MAX; i++) {
		int level = split->level;

		if (split->defaults[i])
			continue;

		for (h = 0; h < q->clhash.hashsize; h++) {
			struct cbq_class *c;

			hlist_for_each_entry(c, &q->clhash.hash[h],
					     common.hnode) {
				if (c->split == split && c->level < level &&
				    c->defmap & (1<<i)) {
					split->defaults[i] = c;
					level = c->level;
				}
			}
		}
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)18491.54%125.00%


Patrick McHardy136.47%125.00%


Stephen Hemminger31.49%125.00%


Eric Dumazet10.50%125.00%


Total201100.00%4100.00%






static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask)
{
	struct cbq_class *split = NULL;

	if (splitid == 0) {
		split = cl->split;
		if (!split)
			return;
		splitid = split->common.classid;
	}

	if (split == NULL || split->common.classid != splitid) {
		for (split = cl->tparent; split; split = split->tparent)
			if (split->common.classid == splitid)
				break;
	}

	if (split == NULL)
		return;

	if (cl->split != split) {
		cl->defmap = 0;
		cbq_sync_defmap(cl);
		cl->split = split;
		cl->defmap = def & mask;
	} else
		cl->defmap = (cl->defmap & ~mask) | (def & mask);

	cbq_sync_defmap(cl);
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)15493.33%133.33%


Patrick McHardy63.64%133.33%


Eric Dumazet53.03%133.33%


Total165100.00%3100.00%






static void cbq_unlink_class(struct cbq_class *this)
{
	struct cbq_class *cl, **clp;
	struct cbq_sched_data *q = qdisc_priv(this->qdisc);

	qdisc_class_hash_remove(&q->clhash, &this->common);

	if (this->tparent) {
		clp = &this->sibling;
		cl = *clp;
		do {
			if (cl == this) {
				*clp = cl->sibling;
				break;
			}
			clp = &cl->sibling;
		} while ((cl = *clp) != this->sibling);

		if (this->tparent->children == this) {
			this->tparent->children = this->sibling;
			if (this->sibling == this)
				this->tparent->children = NULL;
		}
	} else {
		WARN_ON(this->sibling != this);
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)14492.90%125.00%


Patrick McHardy63.87%125.00%


Stephen Hemminger31.94%125.00%


Ilpo Järvinen21.29%125.00%


Total155100.00%4100.00%






static void cbq_link_class(struct cbq_class *this)
{
	struct cbq_sched_data *q = qdisc_priv(this->qdisc);
	struct cbq_class *parent = this->tparent;

	this->sibling = this;
	qdisc_class_hash_insert(&q->clhash, &this->common);

	if (parent == NULL)
		return;

	if (parent->children == NULL) {
		parent->children = this;
	} else {
		this->sibling = parent->children->sibling;
		parent->children->sibling = this;
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)8387.37%250.00%


Patrick McHardy99.47%125.00%


Stephen Hemminger33.16%125.00%


Total95100.00%4100.00%





static void

cbq_reset(struct Qdisc *sch)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *cl;
	int prio;
	unsigned int h;

	q->activemask = 0;
	q->pmask = 0;
	q->tx_class = NULL;
	q->tx_borrowed = NULL;
	qdisc_watchdog_cancel(&q->watchdog);
	hrtimer_cancel(&q->delay_timer);
	q->toplevel = TC_CBQ_MAXLEVEL;
	q->now = psched_get_time();

	for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++)
		q->active[prio] = NULL;

	for (h = 0; h < q->clhash.hashsize; h++) {
		hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
			qdisc_reset(cl->q);

			cl->next_alive = NULL;
			cl->undertime = PSCHED_PASTPERFECT;
			cl->avgidle = cl->maxidle;
			cl->deficit = cl->quantum;
			cl->cpriority = cl->priority;
		}
	}
	sch->q.qlen = 0;
}



Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)16386.70%330.00%


Patrick McHardy2010.64%440.00%


Stephen Hemminger31.60%110.00%


David S. Miller10.53%110.00%


Eric Dumazet10.53%110.00%


Total188100.00%10100.00%






static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss)
{
	if (lss->change & TCF_CBQ_LSS_FLAGS) {
		cl->share = (lss->flags & TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent;
		cl->borrow = (lss->flags & TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent;
	}
	if (lss->change & TCF_CBQ_LSS_EWMA)
		cl->ewma_log = lss->ewma_log;
	if (lss->change & TCF_CBQ_LSS_AVPKT)
		cl->avpkt = lss->avpkt;
	if (lss->change & TCF_CBQ_LSS_MINIDLE)
		cl->minidle = -(long)lss->minidle;
	if (lss->change & TCF_CBQ_LSS_MAXIDLE) {
		cl->maxidle = lss->maxidle;
		cl->avgidle = lss->maxidle;
	}
	if (lss->change & TCF_CBQ_LSS_OFFTIME)
		cl->offtime = lss->offtime;
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)159100.00%2100.00%


Total159100.00%2100.00%






static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl)
{
	q->nclasses[cl->priority]--;
	q->quanta[cl->priority] -= cl->weight;
	cbq_normalize_quanta(q, cl->priority);
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)48100.00%1100.00%


Total48100.00%1100.00%






static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl)
{
	q->nclasses[cl->priority]++;
	q->quanta[cl->priority] += cl->weight;
	cbq_normalize_quanta(q, cl->priority);
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)48100.00%1100.00%


Total48100.00%1100.00%






static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
{
	struct cbq_sched_data *q = qdisc_priv(cl->qdisc);

	if (wrr->allot)
		cl->allot = wrr->allot;
	if (wrr->weight)
		cl->weight = wrr->weight;
	if (wrr->priority) {
		cl->priority = wrr->priority - 1;
		cl->cpriority = cl->priority;
		if (cl->priority >= cl->priority2)
			cl->priority2 = TC_CBQ_MAXPRIO - 1;
	}

	cbq_addprio(q, cl);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6357.27%133.33%


Florian Westphal4440.00%133.33%


Stephen Hemminger32.73%133.33%


Total110100.00%3100.00%






static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt)
{
	cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)36100.00%1100.00%


Total36100.00%1100.00%




static const struct nla_policy cbq_policy[TCA_CBQ_MAX + 1] = {
	[TCA_CBQ_LSSOPT]	= { .len = sizeof(struct tc_cbq_lssopt) },
	[TCA_CBQ_WRROPT]	= { .len = sizeof(struct tc_cbq_wrropt) },
	[TCA_CBQ_FOPT]		= { .len = sizeof(struct tc_cbq_fopt) },
	[TCA_CBQ_OVL_STRATEGY]	= { .len = sizeof(struct tc_cbq_ovl) },
	[TCA_CBQ_RATE]		= { .len = sizeof(struct tc_ratespec) },
	[TCA_CBQ_RTAB]		= { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
	[TCA_CBQ_POLICE]	= { .len = sizeof(struct tc_cbq_police) },
};




static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct nlattr *tb[TCA_CBQ_MAX + 1];
	struct tc_ratespec *r;
	int err;

	err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
	if (err < 0)
		return err;

	if (tb[TCA_CBQ_RTAB] == NULL || tb[TCA_CBQ_RATE] == NULL)
		return -EINVAL;

	r = nla_data(tb[TCA_CBQ_RATE]);

	if ((q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB])) == NULL)
		return -EINVAL;

	err = qdisc_class_hash_init(&q->clhash);
	if (err < 0)
		goto put_rtab;

	q->link.refcnt = 1;
	q->link.sibling = &q->link;
	q->link.common.classid = sch->handle;
	q->link.qdisc = sch;
	q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
				      sch->handle);
	if (!q->link.q)
		q->link.q = &noop_qdisc;

	q->link.priority = TC_CBQ_MAXPRIO - 1;
	q->link.priority2 = TC_CBQ_MAXPRIO - 1;
	q->link.cpriority = TC_CBQ_MAXPRIO - 1;
	q->link.allot = psched_mtu(qdisc_dev(sch));
	q->link.quantum = q->link.allot;
	q->link.weight = q->link.R_tab->rate.rate;

	q->link.ewma_log = TC_CBQ_DEF_EWMA;
	q->link.avpkt = q->link.allot/2;
	q->link.minidle = -0x7FFFFFFF;

	qdisc_watchdog_init(&q->watchdog, sch);
	hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
	q->delay_timer.function = cbq_undelay;
	q->toplevel = TC_CBQ_MAXLEVEL;
	q->now = psched_get_time();

	cbq_link_class(&q->link);

	if (tb[TCA_CBQ_LSSOPT])
		cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));

	cbq_addprio(q, &q->link);
	return 0;

put_rtab:
	qdisc_put_rtab(q->link.R_tab);
	return err;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)32877.73%317.65%


Patrick McHardy7317.30%847.06%


Changli Gao92.13%15.88%


David S. Miller81.90%317.65%


Stephen Hemminger30.71%15.88%


Eric Dumazet10.24%15.88%


Total422100.00%17100.00%






static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
{
	unsigned char *b = skb_tail_pointer(skb);

	if (nla_put(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate))
		goto nla_put_failure;
	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6083.33%120.00%


David S. Miller79.72%120.00%


Arnaldo Carvalho de Melo45.56%240.00%


Patrick McHardy11.39%120.00%


Total72100.00%5100.00%






static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tc_cbq_lssopt opt;

	opt.flags = 0;
	if (cl->borrow == NULL)
		opt.flags |= TCF_CBQ_LSS_BOUNDED;
	if (cl->share == NULL)
		opt.flags |= TCF_CBQ_LSS_ISOLATED;
	opt.ewma_log = cl->ewma_log;
	opt.level = cl->level;
	opt.avpkt = cl->avpkt;
	opt.maxidle = cl->maxidle;
	opt.minidle = (u32)(-cl->minidle);
	opt.offtime = cl->offtime;
	opt.change = ~0;
	if (nla_put(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt))
		goto nla_put_failure;
	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)15192.64%120.00%


David S. Miller74.29%120.00%


Arnaldo Carvalho de Melo42.45%240.00%


Patrick McHardy10.61%120.00%


Total163100.00%5100.00%






static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tc_cbq_wrropt opt;

	memset(&opt, 0, sizeof(opt));
	opt.flags = 0;
	opt.allot = cl->allot;
	opt.priority = cl->priority + 1;
	opt.cpriority = cl->cpriority + 1;
	opt.weight = cl->weight;
	if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt))
		goto nla_put_failure;
	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)9879.67%116.67%


David S. Miller2016.26%233.33%


Arnaldo Carvalho de Melo43.25%233.33%


Patrick McHardy10.81%116.67%


Total123100.00%6100.00%






static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tc_cbq_fopt opt;

	if (cl->split || cl->defmap) {
		opt.split = cl->split ? cl->split->common.classid : 0;
		opt.defmap = cl->defmap;
		opt.defchange = ~0;
		if (nla_put(skb, TCA_CBQ_FOPT, sizeof(opt), &opt))
			goto nla_put_failure;
	}
	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)9987.61%116.67%


David S. Miller76.19%116.67%


Arnaldo Carvalho de Melo43.54%233.33%


Patrick McHardy32.65%233.33%


Total113100.00%6100.00%






static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
{
	if (cbq_dump_lss(skb, cl) < 0 ||
	    cbq_dump_rate(skb, cl) < 0 ||
	    cbq_dump_wrr(skb, cl) < 0 ||
	    cbq_dump_fopt(skb, cl) < 0)
		return -1;
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)61100.00%1100.00%


Total61100.00%1100.00%






static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct nlattr *nest;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
	if (cbq_dump_attr(skb, &q->link) < 0)
		goto nla_put_failure;
	return nla_nest_end(skb, nest);

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)5158.62%225.00%


Patrick McHardy2022.99%225.00%


Thomas Graf1011.49%112.50%


Stephen Hemminger33.45%112.50%


Arnaldo Carvalho de Melo22.30%112.50%


Yang Yingliang11.15%112.50%


Total87100.00%8100.00%





static int

cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
{
	struct cbq_sched_data *q = qdisc_priv(sch);

	q->link.xstats.avgidle = q->link.avgidle;
	return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
}


Contributors
PersonTokensPropCommitsCommitProp
Thomas Graf3454.84%133.33%


Linus Torvalds (pre-git)2845.16%266.67%


Total62100.00%3100.00%





static int

cbq_dump_class(struct Qdisc *sch, unsigned long arg,
	       struct sk_buff *skb, struct tcmsg *tcm)
{
	struct cbq_class *cl = (struct cbq_class *)arg;
	struct nlattr *nest;

	if (cl->tparent)
		tcm->tcm_parent = cl->tparent->common.classid;
	else
		tcm->tcm_parent = TC_H_ROOT;
	tcm->tcm_handle = cl->common.classid;
	tcm->tcm_info = cl->q->handle;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
	if (cbq_dump_attr(skb, cl) < 0)
		goto nla_put_failure;
	return nla_nest_end(skb, nest);

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10172.14%225.00%


Patrick McHardy2417.14%337.50%


Thomas Graf128.57%112.50%


Arnaldo Carvalho de Melo21.43%112.50%


Yang Yingliang10.71%112.50%


Total140100.00%8100.00%





static int

cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	struct gnet_dump *d)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *cl = (struct cbq_class *)arg;

	cl->xstats.avgidle = cl->avgidle;
	cl->xstats.undertime = 0;

	if (cl->undertime != PSCHED_PASTPERFECT)
		cl->xstats.undertime = cl->undertime - q->now;

	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
				  d, NULL, &cl->bstats) < 0 ||
	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
	    gnet_stats_copy_queue(d, NULL, &cl->qstats, cl->q->q.qlen) < 0)
		return -1;

	return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
}


Contributors
PersonTokensPropCommitsCommitProp
Thomas Graf7849.06%111.11%


Linus Torvalds (pre-git)6138.36%222.22%


John Fastabend127.55%333.33%


Eric Dumazet53.14%111.11%


Patrick McHardy31.89%222.22%


Total159100.00%9100.00%






static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
		     struct Qdisc **old)
{
	struct cbq_class *cl = (struct cbq_class *)arg;

	if (new == NULL) {
		new = qdisc_create_dflt(sch->dev_queue,
					&pfifo_qdisc_ops, cl->common.classid);
		if (new == NULL)
			return -ENOBUFS;
	}

	*old = qdisc_replace(sch, new, &cl->q);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6873.91%225.00%


Patrick McHardy1415.22%450.00%


Américo Wang66.52%112.50%


David S. Miller44.35%112.50%


Total92100.00%8100.00%






static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct cbq_class *cl = (struct cbq_class *)arg;

	return cl->q;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)34100.00%1100.00%


Total34100.00%1100.00%






static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
{
	struct cbq_class *cl = (struct cbq_class *)arg;

	if (cl->q->q.qlen == 0)
		cbq_deactivate_class(cl);
}


Contributors
PersonTokensPropCommitsCommitProp
Jarek Poplawski44100.00%1100.00%


Total44100.00%1100.00%






static unsigned long cbq_get(struct Qdisc *sch, u32 classid)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *cl = cbq_class_lookup(q, classid);

	if (cl) {
		cl->refcnt++;
		return (unsigned long)cl;
	}
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)5594.83%150.00%


Stephen Hemminger35.17%150.00%


Total58100.00%2100.00%






static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
{
	struct cbq_sched_data *q = qdisc_priv(sch);

	WARN_ON(cl->filters);

	tcf_destroy_chain(&cl->filter_list);
	qdisc_destroy(cl->q);
	qdisc_put_rtab(cl->R_tab);
	gen_kill_estimator(&cl->rate_est);
	if (cl != &q->link)
		kfree(cl);
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4051.95%225.00%


Patrick McHardy2836.36%337.50%


Thomas Graf810.39%225.00%


Ilpo Järvinen11.30%112.50%


Total77100.00%8100.00%






static void cbq_destroy(struct Qdisc *sch)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct hlist_node *next;
	struct cbq_class *cl;
	unsigned int h;

#ifdef CONFIG_NET_CLS_ACT
	q->rx_class = NULL;
#endif
	/*
         * Filters must be destroyed first because we don't destroy the
         * classes from root to leafs which means that filters can still
         * be bound to classes which have been destroyed already. --TGR '04
         */
	for (h = 0; h < q->clhash.hashsize; h++) {
		hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode)
			tcf_destroy_chain(&cl->filter_list);
	}
	for (h = 0; h < q->clhash.hashsize; h++) {
		hlist_for_each_entry_safe(cl, next, &q->clhash.hash[h],
					  common.hnode)
			cbq_destroy_class(sch, cl);
	}
	qdisc_class_hash_destroy(&q->clhash);
}


Contributors
PersonTokensPropCommitsCommitProp
Patrick McHardy5241.27%753.85%


Linus Torvalds (pre-git)5140.48%215.38%


Thomas Graf1713.49%17.69%


Stephen Hemminger32.38%17.69%


Linus Torvalds21.59%17.69%


Eric Dumazet10.79%17.69%


Total126100.00%13100.00%






static void cbq_put(struct Qdisc *sch, unsigned long arg)
{
	struct cbq_class *cl = (struct cbq_class *)arg;

	if (--cl->refcnt == 0) {
#ifdef CONFIG_NET_CLS_ACT
		spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
		struct cbq_sched_data *q = qdisc_priv(sch);

		spin_lock_bh(root_lock);
		if (q->rx_class == cl)
			q->rx_class = NULL;
		spin_unlock_bh(root_lock);
#endif

		cbq_destroy_class(sch, cl);
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)7479.57%440.00%


David S. Miller1010.75%110.00%


Patrick McHardy55.38%330.00%


Stephen Hemminger33.23%110.00%


Jarek Poplawski11.08%110.00%


Total93100.00%10100.00%





static int

cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
		 unsigned long *arg)
{
	int err;
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *cl = (struct cbq_class *)*arg;
	struct nlattr *opt = tca[TCA_OPTIONS];
	struct nlattr *tb[TCA_CBQ_MAX + 1];
	struct cbq_class *parent;
	struct qdisc_rate_table *rtab = NULL;

	if (opt == NULL)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
	if (err < 0)
		return err;

	if (tb[TCA_CBQ_OVL_STRATEGY] || tb[TCA_CBQ_POLICE])
		return -EOPNOTSUPP;

	if (cl) {
		/* Check parent */
		if (parentid) {
			if (cl->tparent &&
			    cl->tparent->common.classid != parentid)
				return -EINVAL;
			if (!cl->tparent && parentid != TC_H_ROOT)
				return -EINVAL;
		}

		if (tb[TCA_CBQ_RATE]) {
			rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]),
					      tb[TCA_CBQ_RTAB]);
			if (rtab == NULL)
				return -EINVAL;
		}

		if (tca[TCA_RATE]) {
			err = gen_replace_estimator(&cl->bstats, NULL,
						    &cl->rate_est,
						    NULL,
						    qdisc_root_sleeping_running(sch),
						    tca[TCA_RATE]);
			if (err) {
				qdisc_put_rtab(rtab);
				return err;
			}
		}

		/* Change class parameters */
		sch_tree_lock(sch);

		if (cl->next_alive != NULL)
			cbq_deactivate_class(cl);

		if (rtab) {
			qdisc_put_rtab(cl->R_tab);
			cl->R_tab = rtab;
		}

		if (tb[TCA_CBQ_LSSOPT])
			cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));

		if (tb[TCA_CBQ_WRROPT]) {
			cbq_rmprio(q, cl);
			cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
		}

		if (tb[TCA_CBQ_FOPT])
			cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));

		if (cl->q->q.qlen)
			cbq_activate_class(cl);

		sch_tree_unlock(sch);

		return 0;
	}

	if (parentid == TC_H_ROOT)
		return -EINVAL;

	if (tb[TCA_CBQ_WRROPT] == NULL || tb[TCA_CBQ_RATE] == NULL ||
	    tb[TCA_CBQ_LSSOPT] == NULL)
		return -EINVAL;

	rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB]);
	if (rtab == NULL)
		return -EINVAL;

	if (classid) {
		err = -EINVAL;
		if (TC_H_MAJ(classid ^ sch->handle) ||
		    cbq_class_lookup(q, classid))
			goto failure;
	} else {
		int i;
		classid = TC_H_MAKE(sch->handle, 0x8000);

		for (i = 0; i < 0x8000; i++) {
			if (++q->hgenerator >= 0x8000)
				q->hgenerator = 1;
			if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
				break;
		}
		err = -ENOSR;
		if (i >= 0x8000)
			goto failure;
		classid = classid|q->hgenerator;
	}

	parent = &q->link;
	if (parentid) {
		parent = cbq_class_lookup(q, parentid);
		err = -EINVAL;
		if (parent == NULL)
			goto failure;
	}

	err = -ENOBUFS;
	cl = kzalloc(sizeof(*cl), GFP_KERNEL);
	if (cl == NULL)
		goto failure;

	if (tca[TCA_RATE]) {
		err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
					NULL,
					qdisc_root_sleeping_running(sch),
					tca[TCA_RATE]);
		if (err) {
			kfree(cl);
			goto failure;
		}
	}

	cl->R_tab = rtab;
	rtab = NULL;
	cl->refcnt = 1;
	cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid);
	if (!cl->q)
		cl->q = &noop_qdisc;
	cl->common.classid = classid;
	cl->tparent = parent;
	cl->qdisc = sch;
	cl->allot = parent->allot;
	cl->quantum = cl->allot;
	cl->weight = cl->R_tab->rate.rate;

	sch_tree_lock(sch);
	cbq_link_class(cl);
	cl->borrow = cl->tparent;
	if (cl->tparent != &q->link)
		cl->share = cl->tparent;
	cbq_adjust_levels(parent);
	cl->minidle = -0x7FFFFFFF;
	cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
	cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
	if (cl->ewma_log == 0)
		cl->ewma_log = q->link.ewma_log;
	if (cl->maxidle == 0)
		cl->maxidle = q->link.maxidle;
	if (cl->avpkt == 0)
		cl->avpkt = q->link.avpkt;
	if (tb[TCA_CBQ_FOPT])
		cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
	sch_tree_unlock(sch);

	qdisc_class_hash_grow(sch, &q->clhash);

	*arg = (unsigned long)cl;
	return 0;

failure:
	qdisc_put_rtab(rtab);
	return err;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)79280.98%525.00%


Stephen Hemminger979.92%210.00%


Patrick McHardy515.21%630.00%


Florian Westphal161.64%210.00%


Changli Gao70.72%15.00%


Eric Dumazet60.61%15.00%


David S. Miller40.41%15.00%


John Fastabend40.41%15.00%


Panagiotis Issaris10.10%15.00%


Total978100.00%20100.00%






static int cbq_delete(struct Qdisc *sch, unsigned long arg)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *cl = (struct cbq_class *)arg;
	unsigned int qlen, backlog;

	if (cl->filters || cl->children || cl == &q->link)
		return -EBUSY;

	sch_tree_lock(sch);

	qlen = cl->q->q.qlen;
	backlog = cl->q->qstats.backlog;
	qdisc_reset(cl->q);
	qdisc_tree_reduce_backlog(cl->q, qlen, backlog);

	if (cl->next_alive)
		cbq_deactivate_class(cl);

	if (q->tx_borrowed == cl)
		q->tx_borrowed = q->tx_class;
	if (q->tx_class == cl) {
		q->tx_class = NULL;
		q->tx_borrowed = NULL;
	}
#ifdef CONFIG_NET_CLS_ACT
	if (q->rx_class == cl)
		q->rx_class = NULL;
#endif

	cbq_unlink_class(cl);
	cbq_adjust_levels(cl->tparent);
	cl->defmap = 0;
	cbq_sync_defmap(cl);

	cbq_rmprio(q, cl);
	sch_tree_unlock(sch);

	BUG_ON(--cl->refcnt == 0);
	/*
         * This shouldn't happen: we "hold" one cops->get() when called
         * from tc_ctl_tclass; the destroy method is done from cops->put().
         */

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)17176.34%440.00%


Jarek Poplawski3214.29%220.00%


Américo Wang156.70%110.00%


Stephen Hemminger31.34%110.00%


Patrick McHardy31.34%220.00%


Total224100.00%10100.00%






static struct tcf_proto __rcu **cbq_find_tcf(struct Qdisc *sch,
					     unsigned long arg)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *cl = (struct cbq_class *)arg;

	if (cl == NULL)
		cl = &q->link;

	return &cl->filter_list;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)5693.33%250.00%


Stephen Hemminger35.00%125.00%


John Fastabend11.67%125.00%


Total60100.00%4100.00%






static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
				     u32 classid)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *p = (struct cbq_class *)parent;
	struct cbq_class *cl = cbq_class_lookup(q, classid);

	if (cl) {
		if (p && p->level <= cl->level)
			return 0;
		cl->filters++;
		return (unsigned long)cl;
	}
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)8696.63%375.00%


Stephen Hemminger33.37%125.00%


Total89100.00%4100.00%






static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
{
	struct cbq_class *cl = (struct cbq_class *)arg;

	cl->filters--;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)32100.00%2100.00%


Total32100.00%2100.00%






static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
	struct cbq_sched_data *q = qdisc_priv(sch);
	struct cbq_class *cl;
	unsigned int h;

	if (arg->stop)
		return;

	for (h = 0; h < q->clhash.hashsize; h++) {
		hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
			if (arg->count < arg->skip) {
				arg->count++;
				continue;
			}
			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
				arg->stop = 1;
				return;
			}
			arg->count++;
		}
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10081.97%350.00%


Patrick McHardy1814.75%116.67%


Stephen Hemminger32.46%116.67%


Eric Dumazet10.82%116.67%


Total122100.00%6100.00%




static const struct Qdisc_class_ops cbq_class_ops = {
	.graft		=	cbq_graft,
	.leaf		=	cbq_leaf,
	.qlen_notify	=	cbq_qlen_notify,
	.get		=	cbq_get,
	.put		=	cbq_put,
	.change		=	cbq_change_class,
	.delete		=	cbq_delete,
	.walk		=	cbq_walk,
	.tcf_chain	=	cbq_find_tcf,
	.bind_tcf	=	cbq_bind_filter,
	.unbind_tcf	=	cbq_unbind_filter,
	.dump		=	cbq_dump_class,
	.dump_stats	=	cbq_dump_class_stats,
};


static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
	.next		=	NULL,
	.cl_ops		=	&cbq_class_ops,
	.id		=	"cbq",
	.priv_size	=	sizeof(struct cbq_sched_data),
	.enqueue	=	cbq_enqueue,
	.dequeue	=	cbq_dequeue,
	.peek		=	qdisc_peek_dequeued,
	.init		=	cbq_init,
	.reset		=	cbq_reset,
	.destroy	=	cbq_destroy,
	.change		=	NULL,
	.dump		=	cbq_dump,
	.dump_stats	=	cbq_dump_stats,
	.owner		=	THIS_MODULE,
};




static int __init cbq_module_init(void)
{
	return register_qdisc(&cbq_qdisc_ops);
}

Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1381.25%266.67%


Al Viro318.75%133.33%


Total16100.00%3100.00%






static void __exit cbq_module_exit(void)
{
	unregister_qdisc(&cbq_qdisc_ops);
}

Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1280.00%266.67%


Al Viro320.00%133.33%


Total15100.00%3100.00%



module_init(cbq_module_init)
module_exit(cbq_module_exit)
MODULE_LICENSE("GPL");

Overall Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)650077.90%88.08%


Patrick McHardy6567.86%2525.25%


Thomas Graf1812.17%55.05%


Stephen Hemminger1661.99%22.02%


Florian Westphal1651.98%22.02%


Eric Dumazet1621.94%99.09%


Jarek Poplawski1041.25%77.07%


David S. Miller861.03%99.09%


Dave Jones660.79%11.01%


John Fastabend470.56%55.05%


Jamal Hadi Salim460.55%11.01%


Vasily Averin430.52%33.03%


Américo Wang210.25%22.02%


Arnaldo Carvalho de Melo200.24%22.02%


Jussi Kivilinna170.20%22.02%


Changli Gao160.19%11.01%


Al Viro150.18%11.01%


Linus Torvalds90.11%33.03%


Jiri Pirko30.04%11.01%


Daniel Borkmann30.04%11.01%


Yang Yingliang30.04%22.02%


Tejun Heo30.04%11.01%


Vinay K. Nallamothu30.04%11.01%


Ilpo Järvinen30.04%11.01%


Satyam Sharma30.04%11.01%


Hideaki Yoshifuji / 吉藤英明10.01%11.01%


Steven Cole10.01%11.01%


Panagiotis Issaris10.01%11.01%


Total8344100.00%99100.00%


Directory: net/sched



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