sched: sfq: drop packets after root qdisc lock is released

The commit 520ac30f45 ("net_sched: drop packets after root qdisc lock
is released) made a big change of tc for performance. But there are
some points which are not changed in SFQ enqueue operation.
1. Fail to find the SFQ hash slot;
2. When the queue is full;

Now use qdisc_drop instead free skb directly.

Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gao Feng 2017-08-26 22:58:58 +08:00 committed by David S. Miller
parent f7423eea52
commit f9ab7425b3

View File

@ -292,7 +292,7 @@ static inline void slot_queue_add(struct sfq_slot *slot, struct sk_buff *skb)
slot->skblist_prev = skb;
}
static unsigned int sfq_drop(struct Qdisc *sch)
static unsigned int sfq_drop(struct Qdisc *sch, struct sk_buff **to_free)
{
struct sfq_sched_data *q = qdisc_priv(sch);
sfq_index x, d = q->cur_depth;
@ -310,9 +310,8 @@ drop:
slot->backlog -= len;
sfq_dec(q, x);
sch->q.qlen--;
qdisc_qstats_drop(sch);
qdisc_qstats_backlog_dec(sch, skb);
kfree_skb(skb);
qdisc_drop(skb, sch, to_free);
return len;
}
@ -360,7 +359,7 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
if (hash == 0) {
if (ret & __NET_XMIT_BYPASS)
qdisc_qstats_drop(sch);
kfree_skb(skb);
__qdisc_drop(skb, to_free);
return ret;
}
hash--;
@ -465,7 +464,7 @@ enqueue:
return NET_XMIT_SUCCESS;
qlen = slot->qlen;
dropped = sfq_drop(sch);
dropped = sfq_drop(sch, to_free);
/* Return Congestion Notification only if we dropped a packet
* from this flow.
*/
@ -628,6 +627,8 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt)
struct tc_sfq_qopt_v1 *ctl_v1 = NULL;
unsigned int qlen, dropped = 0;
struct red_parms *p = NULL;
struct sk_buff *to_free = NULL;
struct sk_buff *tail = NULL;
if (opt->nla_len < nla_attr_size(sizeof(*ctl)))
return -EINVAL;
@ -674,8 +675,13 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt)
}
qlen = sch->q.qlen;
while (sch->q.qlen > q->limit)
dropped += sfq_drop(sch);
while (sch->q.qlen > q->limit) {
dropped += sfq_drop(sch, &to_free);
if (!tail)
tail = to_free;
}
rtnl_kfree_skbs(to_free, tail);
qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped);
del_timer(&q->perturb_timer);