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| author | Eric Dumazet <edumazet@google.com> | 2016-06-12 20:01:25 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-07-11 09:30:00 -0700 |
| commit | 6a23e18a677464b3e20fed580893efdfd018f80a (patch) | |
| tree | 9f0a972351dfd029895fca0f2cbf1abf9556145c | |
| parent | 9ca505aaffe7bb6f9fe5271256cb0be02928edf2 (diff) | |
| download | lwn-6a23e18a677464b3e20fed580893efdfd018f80a.tar.gz lwn-6a23e18a677464b3e20fed580893efdfd018f80a.zip | |
net_sched: fix pfifo_head_drop behavior vs backlog
[ Upstream commit 6c0d54f1897d229748d4f41ef919078db6db2123 ]
When the qdisc is full, we drop a packet at the head of the queue,
queue the current skb and return NET_XMIT_CN
Now we track backlog on upper qdiscs, we need to call
qdisc_tree_reduce_backlog(), even if the qlen did not change.
Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/sched/sch_fifo.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c index 2177eac0a61e..2e4bd2c0a50c 100644 --- a/net/sched/sch_fifo.c +++ b/net/sched/sch_fifo.c @@ -37,14 +37,18 @@ static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch) static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch) { + unsigned int prev_backlog; + if (likely(skb_queue_len(&sch->q) < sch->limit)) return qdisc_enqueue_tail(skb, sch); + prev_backlog = sch->qstats.backlog; /* queue full, remove one skb to fulfill the limit */ __qdisc_queue_drop_head(sch, &sch->q); qdisc_qstats_drop(sch); qdisc_enqueue_tail(skb, sch); + qdisc_tree_reduce_backlog(sch, 0, prev_backlog - sch->qstats.backlog); return NET_XMIT_CN; } |