summaryrefslogtreecommitdiff
path: root/net/sched/sch_generic.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/sched/sch_generic.c')
-rw-r--r--net/sched/sch_generic.c99
1 files changed, 78 insertions, 21 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index f9e0e9c03..657c13362 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -77,6 +77,34 @@ static void try_bulk_dequeue_skb(struct Qdisc *q,
skb->next = NULL;
}
+/* This variant of try_bulk_dequeue_skb() makes sure
+ * all skbs in the chain are for the same txq
+ */
+static void try_bulk_dequeue_skb_slow(struct Qdisc *q,
+ struct sk_buff *skb,
+ int *packets)
+{
+ int mapping = skb_get_queue_mapping(skb);
+ struct sk_buff *nskb;
+ int cnt = 0;
+
+ do {
+ nskb = q->dequeue(q);
+ if (!nskb)
+ break;
+ if (unlikely(skb_get_queue_mapping(nskb) != mapping)) {
+ q->skb_bad_txq = nskb;
+ qdisc_qstats_backlog_inc(q, nskb);
+ q->q.qlen++;
+ break;
+ }
+ skb->next = nskb;
+ skb = nskb;
+ } while (++cnt < 8);
+ (*packets) += cnt;
+ skb->next = NULL;
+}
+
/* Note that dequeue_skb can possibly return a SKB list (via skb->next).
* A requeued skb (via q->gso_skb) can also be a SKB list.
*/
@@ -87,8 +115,9 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate,
const struct netdev_queue *txq = q->dev_queue;
*packets = 1;
- *validate = true;
if (unlikely(skb)) {
+ /* skb in gso_skb were already validated */
+ *validate = false;
/* check the reason of requeuing without tx lock first */
txq = skb_get_tx_queue(txq->dev, skb);
if (!netif_xmit_frozen_or_stopped(txq)) {
@@ -97,22 +126,37 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate,
q->q.qlen--;
} else
skb = NULL;
- /* skb in gso_skb were already validated */
- *validate = false;
- } else {
- if (!(q->flags & TCQ_F_ONETXQUEUE) ||
- !netif_xmit_frozen_or_stopped(txq)) {
- skb = q->dequeue(q);
- if (skb && qdisc_may_bulk(q))
- try_bulk_dequeue_skb(q, skb, txq, packets);
+ return skb;
+ }
+ *validate = true;
+ skb = q->skb_bad_txq;
+ if (unlikely(skb)) {
+ /* check the reason of requeuing without tx lock first */
+ txq = skb_get_tx_queue(txq->dev, skb);
+ if (!netif_xmit_frozen_or_stopped(txq)) {
+ q->skb_bad_txq = NULL;
+ qdisc_qstats_backlog_dec(q, skb);
+ q->q.qlen--;
+ goto bulk;
}
+ return NULL;
+ }
+ if (!(q->flags & TCQ_F_ONETXQUEUE) ||
+ !netif_xmit_frozen_or_stopped(txq))
+ skb = q->dequeue(q);
+ if (skb) {
+bulk:
+ if (qdisc_may_bulk(q))
+ try_bulk_dequeue_skb(q, skb, txq, packets);
+ else
+ try_bulk_dequeue_skb_slow(q, skb, packets);
}
return skb;
}
/*
* Transmit possibly several skbs, and handle the return status as
- * required. Holding the __QDISC___STATE_RUNNING bit guarantees that
+ * required. Owning running seqcount bit guarantees that
* only one CPU can execute this function.
*
* Returns to the caller:
@@ -165,7 +209,7 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
/*
* NOTE: Called under qdisc_lock(q) with locally disabled BH.
*
- * __QDISC___STATE_RUNNING guarantees only one CPU can process
+ * running seqcount guarantees only one CPU can process
* this qdisc at a time. qdisc_lock(q) serializes queue accesses for
* this queue.
*
@@ -348,9 +392,10 @@ EXPORT_SYMBOL(netif_carrier_off);
cheaper.
*/
-static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc)
+static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
+ struct sk_buff **to_free)
{
- kfree_skb(skb);
+ __qdisc_drop(skb, to_free);
return NET_XMIT_CN;
}
@@ -381,6 +426,7 @@ struct Qdisc noop_qdisc = {
.list = LIST_HEAD_INIT(noop_qdisc.list),
.q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
.dev_queue = &noop_netdev_queue,
+ .running = SEQCNT_ZERO(noop_qdisc.running),
.busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock),
};
EXPORT_SYMBOL(noop_qdisc);
@@ -438,7 +484,8 @@ static inline struct sk_buff_head *band2list(struct pfifo_fast_priv *priv,
return priv->q + band;
}
-static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc)
+static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
+ struct sk_buff **to_free)
{
if (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len) {
int band = prio2band[skb->priority & TC_PRIO_MAX];
@@ -450,7 +497,7 @@ static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc)
return __qdisc_enqueue_tail(skb, qdisc, list);
}
- return qdisc_drop(skb, qdisc);
+ return qdisc_drop(skb, qdisc, to_free);
}
static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
@@ -492,7 +539,7 @@ static void pfifo_fast_reset(struct Qdisc *qdisc)
struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
- __qdisc_reset_queue(qdisc, band2list(priv, prio));
+ __qdisc_reset_queue(band2list(priv, prio));
priv->bitmap = 0;
qdisc->qstats.backlog = 0;
@@ -539,6 +586,7 @@ struct Qdisc_ops pfifo_fast_ops __read_mostly = {
EXPORT_SYMBOL(pfifo_fast_ops);
static struct lock_class_key qdisc_tx_busylock;
+static struct lock_class_key qdisc_running_key;
struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
const struct Qdisc_ops *ops)
@@ -572,6 +620,10 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
lockdep_set_class(&sch->busylock,
dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);
+ seqcount_init(&sch->running);
+ lockdep_set_class(&sch->running,
+ dev->qdisc_running_key ?: &qdisc_running_key);
+
sch->ops = ops;
sch->enqueue = ops->enqueue;
sch->dequeue = ops->dequeue;
@@ -591,18 +643,19 @@ struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
struct Qdisc *sch;
if (!try_module_get(ops->owner))
- goto errout;
+ return NULL;
sch = qdisc_alloc(dev_queue, ops);
- if (IS_ERR(sch))
- goto errout;
+ if (IS_ERR(sch)) {
+ module_put(ops->owner);
+ return NULL;
+ }
sch->parent = parentid;
if (!ops->init || ops->init(sch, NULL) == 0)
return sch;
qdisc_destroy(sch);
-errout:
return NULL;
}
EXPORT_SYMBOL(qdisc_create_dflt);
@@ -616,11 +669,14 @@ void qdisc_reset(struct Qdisc *qdisc)
if (ops->reset)
ops->reset(qdisc);
+ kfree_skb(qdisc->skb_bad_txq);
+ qdisc->skb_bad_txq = NULL;
+
if (qdisc->gso_skb) {
kfree_skb_list(qdisc->gso_skb);
qdisc->gso_skb = NULL;
- qdisc->q.qlen = 0;
}
+ qdisc->q.qlen = 0;
}
EXPORT_SYMBOL(qdisc_reset);
@@ -659,6 +715,7 @@ void qdisc_destroy(struct Qdisc *qdisc)
dev_put(qdisc_dev(qdisc));
kfree_skb_list(qdisc->gso_skb);
+ kfree_skb(qdisc->skb_bad_txq);
/*
* gen_estimator est_timer() might access qdisc->q.lock,
* wait a RCU grace period before freeing qdisc.
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 12:53:41 +0000