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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /net/sched/sch_codel.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/sched/sch_codel.c')
-rw-r--r-- | net/sched/sch_codel.c | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c new file mode 100644 index 0000000000..d7a4874543 --- /dev/null +++ b/net/sched/sch_codel.c @@ -0,0 +1,307 @@ +/* + * Codel - The Controlled-Delay Active Queue Management algorithm + * + * Copyright (C) 2011-2012 Kathleen Nichols <nichols@pollere.com> + * Copyright (C) 2011-2012 Van Jacobson <van@pollere.net> + * + * Implemented on linux by : + * Copyright (C) 2012 Michael D. Taht <dave.taht@bufferbloat.net> + * Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The names of the authors may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * Alternatively, provided that this notice is retained in full, this + * software may be distributed under the terms of the GNU General + * Public License ("GPL") version 2, in which case the provisions of the + * GPL apply INSTEAD OF those given above. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/skbuff.h> +#include <linux/prefetch.h> +#include <net/pkt_sched.h> +#include <net/codel.h> +#include <net/codel_impl.h> +#include <net/codel_qdisc.h> + + +#define DEFAULT_CODEL_LIMIT 1000 + +struct codel_sched_data { + struct codel_params params; + struct codel_vars vars; + struct codel_stats stats; + u32 drop_overlimit; +}; + +/* This is the specific function called from codel_dequeue() + * to dequeue a packet from queue. Note: backlog is handled in + * codel, we dont need to reduce it here. + */ +static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) +{ + struct Qdisc *sch = ctx; + struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); + + if (skb) { + sch->qstats.backlog -= qdisc_pkt_len(skb); + prefetch(&skb->end); /* we'll need skb_shinfo() */ + } + return skb; +} + +static void drop_func(struct sk_buff *skb, void *ctx) +{ + struct Qdisc *sch = ctx; + + kfree_skb(skb); + qdisc_qstats_drop(sch); +} + +static struct sk_buff *codel_qdisc_dequeue(struct Qdisc *sch) +{ + struct codel_sched_data *q = qdisc_priv(sch); + struct sk_buff *skb; + + skb = codel_dequeue(sch, &sch->qstats.backlog, &q->params, &q->vars, + &q->stats, qdisc_pkt_len, codel_get_enqueue_time, + drop_func, dequeue_func); + + /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, + * or HTB crashes. Defer it for next round. + */ + if (q->stats.drop_count && sch->q.qlen) { + qdisc_tree_reduce_backlog(sch, q->stats.drop_count, q->stats.drop_len); + q->stats.drop_count = 0; + q->stats.drop_len = 0; + } + if (skb) + qdisc_bstats_update(sch, skb); + return skb; +} + +static int codel_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, + struct sk_buff **to_free) +{ + struct codel_sched_data *q; + + if (likely(qdisc_qlen(sch) < sch->limit)) { + codel_set_enqueue_time(skb); + return qdisc_enqueue_tail(skb, sch); + } + q = qdisc_priv(sch); + q->drop_overlimit++; + return qdisc_drop(skb, sch, to_free); +} + +static const struct nla_policy codel_policy[TCA_CODEL_MAX + 1] = { + [TCA_CODEL_TARGET] = { .type = NLA_U32 }, + [TCA_CODEL_LIMIT] = { .type = NLA_U32 }, + [TCA_CODEL_INTERVAL] = { .type = NLA_U32 }, + [TCA_CODEL_ECN] = { .type = NLA_U32 }, + [TCA_CODEL_CE_THRESHOLD]= { .type = NLA_U32 }, +}; + +static int codel_change(struct Qdisc *sch, struct nlattr *opt, + struct netlink_ext_ack *extack) +{ + struct codel_sched_data *q = qdisc_priv(sch); + struct nlattr *tb[TCA_CODEL_MAX + 1]; + unsigned int qlen, dropped = 0; + int err; + + err = nla_parse_nested_deprecated(tb, TCA_CODEL_MAX, opt, + codel_policy, NULL); + if (err < 0) + return err; + + sch_tree_lock(sch); + + if (tb[TCA_CODEL_TARGET]) { + u32 target = nla_get_u32(tb[TCA_CODEL_TARGET]); + + q->params.target = ((u64)target * NSEC_PER_USEC) >> CODEL_SHIFT; + } + + if (tb[TCA_CODEL_CE_THRESHOLD]) { + u64 val = nla_get_u32(tb[TCA_CODEL_CE_THRESHOLD]); + + q->params.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; + } + + if (tb[TCA_CODEL_INTERVAL]) { + u32 interval = nla_get_u32(tb[TCA_CODEL_INTERVAL]); + + q->params.interval = ((u64)interval * NSEC_PER_USEC) >> CODEL_SHIFT; + } + + if (tb[TCA_CODEL_LIMIT]) + sch->limit = nla_get_u32(tb[TCA_CODEL_LIMIT]); + + if (tb[TCA_CODEL_ECN]) + q->params.ecn = !!nla_get_u32(tb[TCA_CODEL_ECN]); + + qlen = sch->q.qlen; + while (sch->q.qlen > sch->limit) { + struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); + + dropped += qdisc_pkt_len(skb); + qdisc_qstats_backlog_dec(sch, skb); + rtnl_qdisc_drop(skb, sch); + } + qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped); + + sch_tree_unlock(sch); + return 0; +} + +static int codel_init(struct Qdisc *sch, struct nlattr *opt, + struct netlink_ext_ack *extack) +{ + struct codel_sched_data *q = qdisc_priv(sch); + + sch->limit = DEFAULT_CODEL_LIMIT; + + codel_params_init(&q->params); + codel_vars_init(&q->vars); + codel_stats_init(&q->stats); + q->params.mtu = psched_mtu(qdisc_dev(sch)); + + if (opt) { + int err = codel_change(sch, opt, extack); + + if (err) + return err; + } + + if (sch->limit >= 1) + sch->flags |= TCQ_F_CAN_BYPASS; + else + sch->flags &= ~TCQ_F_CAN_BYPASS; + + return 0; +} + +static int codel_dump(struct Qdisc *sch, struct sk_buff *skb) +{ + struct codel_sched_data *q = qdisc_priv(sch); + struct nlattr *opts; + + opts = nla_nest_start_noflag(skb, TCA_OPTIONS); + if (opts == NULL) + goto nla_put_failure; + + if (nla_put_u32(skb, TCA_CODEL_TARGET, + codel_time_to_us(q->params.target)) || + nla_put_u32(skb, TCA_CODEL_LIMIT, + sch->limit) || + nla_put_u32(skb, TCA_CODEL_INTERVAL, + codel_time_to_us(q->params.interval)) || + nla_put_u32(skb, TCA_CODEL_ECN, + q->params.ecn)) + goto nla_put_failure; + if (q->params.ce_threshold != CODEL_DISABLED_THRESHOLD && + nla_put_u32(skb, TCA_CODEL_CE_THRESHOLD, + codel_time_to_us(q->params.ce_threshold))) + goto nla_put_failure; + return nla_nest_end(skb, opts); + +nla_put_failure: + nla_nest_cancel(skb, opts); + return -1; +} + +static int codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) +{ + const struct codel_sched_data *q = qdisc_priv(sch); + struct tc_codel_xstats st = { + .maxpacket = q->stats.maxpacket, + .count = q->vars.count, + .lastcount = q->vars.lastcount, + .drop_overlimit = q->drop_overlimit, + .ldelay = codel_time_to_us(q->vars.ldelay), + .dropping = q->vars.dropping, + .ecn_mark = q->stats.ecn_mark, + .ce_mark = q->stats.ce_mark, + }; + + if (q->vars.dropping) { + codel_tdiff_t delta = q->vars.drop_next - codel_get_time(); + + if (delta >= 0) + st.drop_next = codel_time_to_us(delta); + else + st.drop_next = -codel_time_to_us(-delta); + } + + return gnet_stats_copy_app(d, &st, sizeof(st)); +} + +static void codel_reset(struct Qdisc *sch) +{ + struct codel_sched_data *q = qdisc_priv(sch); + + qdisc_reset_queue(sch); + codel_vars_init(&q->vars); +} + +static struct Qdisc_ops codel_qdisc_ops __read_mostly = { + .id = "codel", + .priv_size = sizeof(struct codel_sched_data), + + .enqueue = codel_qdisc_enqueue, + .dequeue = codel_qdisc_dequeue, + .peek = qdisc_peek_dequeued, + .init = codel_init, + .reset = codel_reset, + .change = codel_change, + .dump = codel_dump, + .dump_stats = codel_dump_stats, + .owner = THIS_MODULE, +}; + +static int __init codel_module_init(void) +{ + return register_qdisc(&codel_qdisc_ops); +} + +static void __exit codel_module_exit(void) +{ + unregister_qdisc(&codel_qdisc_ops); +} + +module_init(codel_module_init) +module_exit(codel_module_exit) + +MODULE_DESCRIPTION("Controlled Delay queue discipline"); +MODULE_AUTHOR("Dave Taht"); +MODULE_AUTHOR("Eric Dumazet"); +MODULE_LICENSE("Dual BSD/GPL"); |