--- /dev/null
+/*
+ * net/sched/sch_drr.c Deficit Round Robin scheduler
+ *
+ * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/pkt_sched.h>
+#include <net/sch_generic.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+
+struct drr_class {
+ struct Qdisc_class_common common;
+ unsigned int refcnt;
+ unsigned int filter_cnt;
+
+ struct gnet_stats_basic_packed bstats;
+ struct gnet_stats_queue qstats;
+ struct gnet_stats_rate_est64 rate_est;
+ struct list_head alist;
+ struct Qdisc *qdisc;
+
+ u32 quantum;
+ u32 deficit;
+};
+
+struct drr_sched {
+ struct list_head active;
+ struct tcf_proto __rcu *filter_list;
+ struct Qdisc_class_hash clhash;
+};
+
+static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct Qdisc_class_common *clc;
+
+ clc = qdisc_class_find(&q->clhash, classid);
+ if (clc == NULL)
+ return NULL;
+ return container_of(clc, struct drr_class, common);
+}
+
+static void drr_purge_queue(struct drr_class *cl)
+{
+ unsigned int len = cl->qdisc->q.qlen;
+
+ qdisc_reset(cl->qdisc);
+ qdisc_tree_decrease_qlen(cl->qdisc, len);
+}
+
+static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
+ [TCA_DRR_QUANTUM] = { .type = NLA_U32 },
+};
+
+static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
+ struct nlattr **tca, unsigned long *arg)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct drr_class *cl = (struct drr_class *)*arg;
+ struct nlattr *opt = tca[TCA_OPTIONS];
+ struct nlattr *tb[TCA_DRR_MAX + 1];
+ u32 quantum;
+ int err;
+
+ if (!opt)
+ return -EINVAL;
+
+ err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
+ if (err < 0)
+ return err;
+
+ if (tb[TCA_DRR_QUANTUM]) {
+ quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
+ if (quantum == 0)
+ return -EINVAL;
+ } else
+ quantum = psched_mtu(qdisc_dev(sch));
+
+ if (cl != NULL) {
+ if (tca[TCA_RATE]) {
+ err = gen_replace_estimator(&cl->bstats, NULL,
+ &cl->rate_est,
+ qdisc_root_sleeping_lock(sch),
+ tca[TCA_RATE]);
+ if (err)
+ return err;
+ }
+
+ sch_tree_lock(sch);
+ if (tb[TCA_DRR_QUANTUM])
+ cl->quantum = quantum;
+ sch_tree_unlock(sch);
+
+ return 0;
+ }
+
+ cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
+ if (cl == NULL)
+ return -ENOBUFS;
+
+ cl->refcnt = 1;
+ cl->common.classid = classid;
+ cl->quantum = quantum;
+ cl->qdisc = qdisc_create_dflt(sch->dev_queue,
+ &pfifo_qdisc_ops, classid);
+ if (cl->qdisc == NULL)
+ cl->qdisc = &noop_qdisc;
+
+ if (tca[TCA_RATE]) {
+ err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
+ qdisc_root_sleeping_lock(sch),
+ tca[TCA_RATE]);
+ if (err) {
+ qdisc_destroy(cl->qdisc);
+ kfree(cl);
+ return err;
+ }
+ }
+
+ sch_tree_lock(sch);
+ qdisc_class_hash_insert(&q->clhash, &cl->common);
+ sch_tree_unlock(sch);
+
+ qdisc_class_hash_grow(sch, &q->clhash);
+
+ *arg = (unsigned long)cl;
+ return 0;
+}
+
+static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
+{
+ gen_kill_estimator(&cl->bstats, &cl->rate_est);
+ qdisc_destroy(cl->qdisc);
+ kfree(cl);
+}
+
+static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct drr_class *cl = (struct drr_class *)arg;
+
+ if (cl->filter_cnt > 0)
+ return -EBUSY;
+
+ sch_tree_lock(sch);
+
+ drr_purge_queue(cl);
+ qdisc_class_hash_remove(&q->clhash, &cl->common);
+
+ 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().
+ */
+
+ sch_tree_unlock(sch);
+ return 0;
+}
+
+static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
+{
+ struct drr_class *cl = drr_find_class(sch, classid);
+
+ if (cl != NULL)
+ cl->refcnt++;
+
+ return (unsigned long)cl;
+}
+
+static void drr_put_class(struct Qdisc *sch, unsigned long arg)
+{
+ struct drr_class *cl = (struct drr_class *)arg;
+
+ if (--cl->refcnt == 0)
+ drr_destroy_class(sch, cl);
+}
+
+static struct tcf_proto __rcu **drr_tcf_chain(struct Qdisc *sch,
+ unsigned long cl)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+
+ if (cl)
+ return NULL;
+
+ return &q->filter_list;
+}
+
+static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
+ u32 classid)
+{
+ struct drr_class *cl = drr_find_class(sch, classid);
+
+ if (cl != NULL)
+ cl->filter_cnt++;
+
+ return (unsigned long)cl;
+}
+
+static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
+{
+ struct drr_class *cl = (struct drr_class *)arg;
+
+ cl->filter_cnt--;
+}
+
+static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
+ struct Qdisc *new, struct Qdisc **old)
+{
+ struct drr_class *cl = (struct drr_class *)arg;
+
+ if (new == NULL) {
+ new = qdisc_create_dflt(sch->dev_queue,
+ &pfifo_qdisc_ops, cl->common.classid);
+ if (new == NULL)
+ new = &noop_qdisc;
+ }
+
+ sch_tree_lock(sch);
+ drr_purge_queue(cl);
+ *old = cl->qdisc;
+ cl->qdisc = new;
+ sch_tree_unlock(sch);
+ return 0;
+}
+
+static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
+{
+ struct drr_class *cl = (struct drr_class *)arg;
+
+ return cl->qdisc;
+}
+
+static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
+{
+ struct drr_class *cl = (struct drr_class *)arg;
+
+ if (cl->qdisc->q.qlen == 0)
+ list_del(&cl->alist);
+}
+
+static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
+ struct sk_buff *skb, struct tcmsg *tcm)
+{
+ struct drr_class *cl = (struct drr_class *)arg;
+ struct nlattr *nest;
+
+ tcm->tcm_parent = TC_H_ROOT;
+ tcm->tcm_handle = cl->common.classid;
+ tcm->tcm_info = cl->qdisc->handle;
+
+ nest = nla_nest_start(skb, TCA_OPTIONS);
+ if (nest == NULL)
+ goto nla_put_failure;
+ if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
+ goto nla_put_failure;
+ return nla_nest_end(skb, nest);
+
+nla_put_failure:
+ nla_nest_cancel(skb, nest);
+ return -EMSGSIZE;
+}
+
+static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
+ struct gnet_dump *d)
+{
+ struct drr_class *cl = (struct drr_class *)arg;
+ __u32 qlen = cl->qdisc->q.qlen;
+ struct tc_drr_stats xstats;
+
+ memset(&xstats, 0, sizeof(xstats));
+ if (qlen)
+ xstats.deficit = cl->deficit;
+
+ if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
+ gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
+ gnet_stats_copy_queue(d, NULL, &cl->qdisc->qstats, qlen) < 0)
+ return -1;
+
+ return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
+}
+
+static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct drr_class *cl;
+ unsigned int i;
+
+ if (arg->stop)
+ return;
+
+ for (i = 0; i < q->clhash.hashsize; i++) {
+ hlist_for_each_entry(cl, &q->clhash.hash[i], 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++;
+ }
+ }
+}
+
+static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
+ int *qerr)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct drr_class *cl;
+ struct tcf_result res;
+ struct tcf_proto *fl;
+ int result;
+
+ if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
+ cl = drr_find_class(sch, skb->priority);
+ if (cl != NULL)
+ return cl;
+ }
+
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+ fl = rcu_dereference_bh(q->filter_list);
+ result = tc_classify(skb, fl, &res);
+ if (result >= 0) {
+#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;
+ }
+#endif
+ cl = (struct drr_class *)res.class;
+ if (cl == NULL)
+ cl = drr_find_class(sch, res.classid);
+ return cl;
+ }
+ return NULL;
+}
+
+static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct drr_class *cl;
+ int err = 0;
+
+ cl = drr_classify(skb, sch, &err);
+ if (cl == NULL) {
+ if (err & __NET_XMIT_BYPASS)
+ qdisc_qstats_drop(sch);
+ kfree_skb(skb);
+ return err;
+ }
+
+ err = qdisc_enqueue(skb, cl->qdisc);
+ if (unlikely(err != NET_XMIT_SUCCESS)) {
+ if (net_xmit_drop_count(err)) {
+ cl->qstats.drops++;
+ qdisc_qstats_drop(sch);
+ }
+ return err;
+ }
+
+ if (cl->qdisc->q.qlen == 1) {
+ list_add_tail(&cl->alist, &q->active);
+ cl->deficit = cl->quantum;
+ }
+
+ sch->q.qlen++;
+ return err;
+}
+
+static struct sk_buff *drr_dequeue(struct Qdisc *sch)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct drr_class *cl;
+ struct sk_buff *skb;
+ unsigned int len;
+
+ if (list_empty(&q->active))
+ goto out;
+ while (1) {
+ cl = list_first_entry(&q->active, struct drr_class, alist);
+ skb = cl->qdisc->ops->peek(cl->qdisc);
+ if (skb == NULL) {
+ qdisc_warn_nonwc(__func__, cl->qdisc);
+ goto out;
+ }
+
+ len = qdisc_pkt_len(skb);
+ if (len <= cl->deficit) {
+ cl->deficit -= len;
+ skb = qdisc_dequeue_peeked(cl->qdisc);
+ if (cl->qdisc->q.qlen == 0)
+ list_del(&cl->alist);
+
+ bstats_update(&cl->bstats, skb);
+ qdisc_bstats_update(sch, skb);
+ sch->q.qlen--;
+ return skb;
+ }
+
+ cl->deficit += cl->quantum;
+ list_move_tail(&cl->alist, &q->active);
+ }
+out:
+ return NULL;
+}
+
+static unsigned int drr_drop(struct Qdisc *sch)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct drr_class *cl;
+ unsigned int len;
+
+ list_for_each_entry(cl, &q->active, alist) {
+ if (cl->qdisc->ops->drop) {
+ len = cl->qdisc->ops->drop(cl->qdisc);
+ if (len > 0) {
+ sch->q.qlen--;
+ if (cl->qdisc->q.qlen == 0)
+ list_del(&cl->alist);
+ return len;
+ }
+ }
+ }
+ return 0;
+}
+
+static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ int err;
+
+ err = qdisc_class_hash_init(&q->clhash);
+ if (err < 0)
+ return err;
+ INIT_LIST_HEAD(&q->active);
+ return 0;
+}
+
+static void drr_reset_qdisc(struct Qdisc *sch)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct drr_class *cl;
+ unsigned int i;
+
+ for (i = 0; i < q->clhash.hashsize; i++) {
+ hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
+ if (cl->qdisc->q.qlen)
+ list_del(&cl->alist);
+ qdisc_reset(cl->qdisc);
+ }
+ }
+ sch->q.qlen = 0;
+}
+
+static void drr_destroy_qdisc(struct Qdisc *sch)
+{
+ struct drr_sched *q = qdisc_priv(sch);
+ struct drr_class *cl;
+ struct hlist_node *next;
+ unsigned int i;
+
+ tcf_destroy_chain(&q->filter_list);
+
+ for (i = 0; i < q->clhash.hashsize; i++) {
+ hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
+ common.hnode)
+ drr_destroy_class(sch, cl);
+ }
+ qdisc_class_hash_destroy(&q->clhash);
+}
+
+static const struct Qdisc_class_ops drr_class_ops = {
+ .change = drr_change_class,
+ .delete = drr_delete_class,
+ .get = drr_get_class,
+ .put = drr_put_class,
+ .tcf_chain = drr_tcf_chain,
+ .bind_tcf = drr_bind_tcf,
+ .unbind_tcf = drr_unbind_tcf,
+ .graft = drr_graft_class,
+ .leaf = drr_class_leaf,
+ .qlen_notify = drr_qlen_notify,
+ .dump = drr_dump_class,
+ .dump_stats = drr_dump_class_stats,
+ .walk = drr_walk,
+};
+
+static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
+ .cl_ops = &drr_class_ops,
+ .id = "drr",
+ .priv_size = sizeof(struct drr_sched),
+ .enqueue = drr_enqueue,
+ .dequeue = drr_dequeue,
+ .peek = qdisc_peek_dequeued,
+ .drop = drr_drop,
+ .init = drr_init_qdisc,
+ .reset = drr_reset_qdisc,
+ .destroy = drr_destroy_qdisc,
+ .owner = THIS_MODULE,
+};
+
+static int __init drr_init(void)
+{
+ return register_qdisc(&drr_qdisc_ops);
+}
+
+static void __exit drr_exit(void)
+{
+ unregister_qdisc(&drr_qdisc_ops);
+}
+
+module_init(drr_init);
+module_exit(drr_exit);
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff