Subject: Re: [PATCH net-next] net_sched: increase drops and decrease backlog when packets are dropped

From: Yang Yingliang <[email-masked]>
Date: Thu, 8 May 2014 10:08:15 +0800

On 2014/5/6 21:58, Eric Dumazet wrote:
> On Tue, 2014-05-06 at 17:37 +0800, Yang Yingliang wrote:
>> When packets are dropped, backlog and drops statistic of qdisc
>> need be changed. Replace kfree_skb() with qdisc_drop() for
>> increasing drops.
>>
>> Signed-off-by: Yang Yingliang <[email-masked]>
>> ---
> 
> 
>> diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
>> index 0bf432c782c1..83abd4cd10cd 100644
>> --- a/net/sched/sch_fq_codel.c
>> +++ b/net/sched/sch_fq_codel.c
>> @@ -344,7 +344,8 @@ static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt)
>>  	while (sch->q.qlen > sch->limit) {
>>  		struct sk_buff *skb = fq_codel_dequeue(sch);
>>  
>> -		kfree_skb(skb);
>> +		sch->qstats.backlog -= qdisc_pkt_len(skb);
> 
> Hmmm... please describe how you tested this change ?

Compiled only. The packet is dropped, so I think the backlog should be decreased.

Regards,
Yang

> 
>> +		qdisc_drop(skb, sch);
>>  		q->cstats.drop_count++;
>>  	}
>>  	qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
> 
> 
> 
>