diff options
| author | Florian Westphal <fw@strlen.de> | 2016-09-18 00:57:34 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-09-19 01:47:18 -0400 |
| commit | 48da34b7a74201f15315cb1fc40bb9a7bd2b4940 (patch) | |
| tree | 123595224534ee49f1175b6ef8371728b6d31538 /net/sched/sch_htb.c | |
| parent | ed760cb8aae7c2b84c193d4a7637b0c9e752f07e (diff) | |
| download | linux-48da34b7a74201f15315cb1fc40bb9a7bd2b4940.tar.bz2 | |
sched: add and use qdisc_skb_head helpers
This change replaces sk_buff_head struct in Qdiscs with new qdisc_skb_head.
Its similar to the skb_buff_head api, but does not use skb->prev pointers.
Qdiscs will commonly enqueue at the tail of a list and dequeue at head.
While skb_buff_head works fine for this, enqueue/dequeue needs to also
adjust the prev pointer of next element.
The ->prev pointer is not required for qdiscs so we can just leave
it undefined and avoid one cacheline write access for en/dequeue.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_htb.c')
| -rw-r--r-- | net/sched/sch_htb.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 53dbfa187870..c798d0de8a9d 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -162,7 +162,7 @@ struct htb_sched { struct work_struct work; /* non shaped skbs; let them go directly thru */ - struct sk_buff_head direct_queue; + struct qdisc_skb_head direct_queue; long direct_pkts; struct qdisc_watchdog watchdog; @@ -570,6 +570,22 @@ static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl) list_del_init(&cl->un.leaf.drop_list); } +static void htb_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, + struct qdisc_skb_head *qh) +{ + struct sk_buff *last = qh->tail; + + if (last) { + skb->next = NULL; + last->next = skb; + qh->tail = skb; + } else { + qh->tail = skb; + qh->head = skb; + } + qh->qlen++; +} + static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { @@ -580,7 +596,7 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch, if (cl == HTB_DIRECT) { /* enqueue to helper queue */ if (q->direct_queue.qlen < q->direct_qlen) { - __skb_queue_tail(&q->direct_queue, skb); + htb_enqueue_tail(skb, sch, &q->direct_queue); q->direct_pkts++; } else { return qdisc_drop(skb, sch, to_free); @@ -888,7 +904,7 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch) unsigned long start_at; /* try to dequeue direct packets as high prio (!) to minimize cpu work */ - skb = __skb_dequeue(&q->direct_queue); + skb = __qdisc_dequeue_head(&q->direct_queue); if (skb != NULL) { ok: qdisc_bstats_update(sch, skb); @@ -1019,7 +1035,7 @@ static int htb_init(struct Qdisc *sch, struct nlattr *opt) qdisc_watchdog_init(&q->watchdog, sch); INIT_WORK(&q->work, htb_work_func); - __skb_queue_head_init(&q->direct_queue); + qdisc_skb_head_init(&q->direct_queue); if (tb[TCA_HTB_DIRECT_QLEN]) q->direct_qlen = nla_get_u32(tb[TCA_HTB_DIRECT_QLEN]); |