From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/net/sched/sch_netem.c | 146 ++++++++++++++++++++++++++++--------------------
1 files changed, 86 insertions(+), 60 deletions(-)
diff --git a/kernel/net/sched/sch_netem.c b/kernel/net/sched/sch_netem.c
index ad400f4..adc5407 100644
--- a/kernel/net/sched/sch_netem.c
+++ b/kernel/net/sched/sch_netem.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* net/sched/sch_netem.c Network emulator
- *
- * 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.
*
* Many of the algorithms and ideas for this came from
* NIST Net which is not copyrighted.
@@ -70,12 +66,16 @@
struct disttable {
u32 size;
- s16 table[0];
+ s16 table[];
};
struct netem_sched_data {
/* internal t(ime)fifo qdisc uses t_root and sch->limit */
struct rb_root t_root;
+
+ /* a linear queue; reduces rbtree rebalancing when jitter is low */
+ struct sk_buff *t_head;
+ struct sk_buff *t_tail;
/* optional qdisc for classful handling (NULL at netem init) */
struct Qdisc *qdisc;
@@ -369,26 +369,39 @@
rb_erase(&skb->rbnode, &q->t_root);
rtnl_kfree_skbs(skb, skb);
}
+
+ rtnl_kfree_skbs(q->t_head, q->t_tail);
+ q->t_head = NULL;
+ q->t_tail = NULL;
}
static void tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
u64 tnext = netem_skb_cb(nskb)->time_to_send;
- struct rb_node **p = &q->t_root.rb_node, *parent = NULL;
- while (*p) {
- struct sk_buff *skb;
-
- parent = *p;
- skb = rb_to_skb(parent);
- if (tnext >= netem_skb_cb(skb)->time_to_send)
- p = &parent->rb_right;
+ if (!q->t_tail || tnext >= netem_skb_cb(q->t_tail)->time_to_send) {
+ if (q->t_tail)
+ q->t_tail->next = nskb;
else
- p = &parent->rb_left;
+ q->t_head = nskb;
+ q->t_tail = nskb;
+ } else {
+ struct rb_node **p = &q->t_root.rb_node, *parent = NULL;
+
+ while (*p) {
+ struct sk_buff *skb;
+
+ parent = *p;
+ skb = rb_to_skb(parent);
+ if (tnext >= netem_skb_cb(skb)->time_to_send)
+ p = &parent->rb_right;
+ else
+ p = &parent->rb_left;
+ }
+ rb_link_node(&nskb->rbnode, parent, p);
+ rb_insert_color(&nskb->rbnode, &q->t_root);
}
- rb_link_node(&nskb->rbnode, parent, p);
- rb_insert_color(&nskb->rbnode, &q->t_root);
sch->q.qlen++;
}
@@ -410,16 +423,6 @@
}
consume_skb(skb);
return segs;
-}
-
-static void netem_enqueue_skb_head(struct qdisc_skb_head *qh, struct sk_buff *skb)
-{
- skb->next = qh->head;
-
- if (!qh->head)
- qh->tail = skb;
- qh->head = skb;
- qh->qlen++;
}
/*
@@ -490,16 +493,13 @@
*/
if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) {
if (skb_is_gso(skb)) {
- segs = netem_segment(skb, sch, to_free);
- if (!segs)
+ skb = netem_segment(skb, sch, to_free);
+ if (!skb)
return rc_drop;
- qdisc_skb_cb(segs)->pkt_len = segs->len;
- } else {
- segs = skb;
+ segs = skb->next;
+ skb_mark_not_on_list(skb);
+ qdisc_skb_cb(skb)->pkt_len = skb->len;
}
-
- skb = segs;
- segs = segs->next;
skb = skb_unshare(skb, GFP_ATOMIC);
if (unlikely(!skb)) {
@@ -518,6 +518,8 @@
}
if (unlikely(sch->q.qlen >= sch->limit)) {
+ /* re-link segs, so that qdisc_drop_all() frees them all */
+ skb->next = segs;
qdisc_drop_all(skb, sch, to_free);
return rc_drop;
}
@@ -548,9 +550,16 @@
t_skb = skb_rb_last(&q->t_root);
t_last = netem_skb_cb(t_skb);
if (!last ||
- t_last->time_to_send > last->time_to_send) {
+ t_last->time_to_send > last->time_to_send)
last = t_last;
- }
+ }
+ if (q->t_tail) {
+ struct netem_skb_cb *t_last =
+ netem_skb_cb(q->t_tail);
+
+ if (!last ||
+ t_last->time_to_send > last->time_to_send)
+ last = t_last;
}
if (last) {
@@ -578,7 +587,7 @@
cb->time_to_send = ktime_get_ns();
q->counter = 0;
- netem_enqueue_skb_head(&sch->q, skb);
+ __qdisc_enqueue_head(skb, &sch->q);
sch->qstats.requeues++;
}
@@ -592,7 +601,7 @@
while (segs) {
skb2 = segs->next;
- segs->next = NULL;
+ skb_mark_not_on_list(segs);
qdisc_skb_cb(segs)->pkt_len = segs->len;
last_len = segs->len;
rc = qdisc_enqueue(segs, sch, to_free);
@@ -636,11 +645,38 @@
q->slot.bytes_left = q->slot_config.max_bytes;
}
+static struct sk_buff *netem_peek(struct netem_sched_data *q)
+{
+ struct sk_buff *skb = skb_rb_first(&q->t_root);
+ u64 t1, t2;
+
+ if (!skb)
+ return q->t_head;
+ if (!q->t_head)
+ return skb;
+
+ t1 = netem_skb_cb(skb)->time_to_send;
+ t2 = netem_skb_cb(q->t_head)->time_to_send;
+ if (t1 < t2)
+ return skb;
+ return q->t_head;
+}
+
+static void netem_erase_head(struct netem_sched_data *q, struct sk_buff *skb)
+{
+ if (skb == q->t_head) {
+ q->t_head = skb->next;
+ if (!q->t_head)
+ q->t_tail = NULL;
+ } else {
+ rb_erase(&skb->rbnode, &q->t_root);
+ }
+}
+
static struct sk_buff *netem_dequeue(struct Qdisc *sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
struct sk_buff *skb;
- struct rb_node *p;
tfifo_dequeue:
skb = __qdisc_dequeue_head(&sch->q);
@@ -650,20 +686,18 @@
qdisc_bstats_update(sch, skb);
return skb;
}
- p = rb_first(&q->t_root);
- if (p) {
+ skb = netem_peek(q);
+ if (skb) {
u64 time_to_send;
u64 now = ktime_get_ns();
-
- skb = rb_to_skb(p);
/* if more time remaining? */
time_to_send = netem_skb_cb(skb)->time_to_send;
if (q->slot.slot_next && q->slot.slot_next < time_to_send)
get_slot_next(q, now);
- if (time_to_send <= now && q->slot.slot_next <= now) {
- rb_erase(p, &q->t_root);
+ if (time_to_send <= now && q->slot.slot_next <= now) {
+ netem_erase_head(q, skb);
sch->q.qlen--;
qdisc_qstats_backlog_dec(sch, skb);
skb->next = NULL;
@@ -672,15 +706,6 @@
* we need to restore its value.
*/
skb->dev = qdisc_dev(sch);
-
-#ifdef CONFIG_NET_CLS_ACT
- /*
- * If it's at ingress let's pretend the delay is
- * from the network (tstamp will be updated).
- */
- if (skb->tc_redirected && skb->tc_from_ingress)
- skb->tstamp = 0;
-#endif
if (q->slot.slot_next) {
q->slot.packets_left--;
@@ -917,8 +942,9 @@
}
if (nested_len >= nla_attr_size(0))
- return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len),
- nested_len, policy, NULL);
+ return nla_parse_deprecated(tb, maxtype,
+ nla_data(nla) + NLA_ALIGN(len),
+ nested_len, policy, NULL);
memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
return 0;
@@ -1064,7 +1090,7 @@
{
struct nlattr *nest;
- nest = nla_nest_start(skb, TCA_NETEM_LOSS);
+ nest = nla_nest_start_noflag(skb, TCA_NETEM_LOSS);
if (nest == NULL)
goto nla_put_failure;
@@ -1120,9 +1146,9 @@
struct tc_netem_rate rate;
struct tc_netem_slot slot;
- qopt.latency = min_t(psched_tdiff_t, PSCHED_NS2TICKS(q->latency),
+ qopt.latency = min_t(psched_time_t, PSCHED_NS2TICKS(q->latency),
UINT_MAX);
- qopt.jitter = min_t(psched_tdiff_t, PSCHED_NS2TICKS(q->jitter),
+ qopt.jitter = min_t(psched_time_t, PSCHED_NS2TICKS(q->jitter),
UINT_MAX);
qopt.limit = q->limit;
qopt.loss = q->loss;
--
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