From: Gao Feng <gfree.wind@vip.163.com>
Date: Sat, 26 Aug 2017 22:58:58 +0800
Subject: sched: sfq: drop packets after root qdisc lock is released
Patch-mainline: v4.14-rc1
Git-commit: f9ab7425b312f8a41339389e83b238c3242e8429
References: bsc#1109837
The commit 520ac30f4551 ("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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/sched/sch_sfq.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -292,7 +292,7 @@ static inline void slot_queue_add(struct
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
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 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,
}
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);