On 15.06.2018 16:13, Eric Dumazet wrote:
On 06/15/2018 03:27 AM, Konstantin Khlebnikov wrote:When blackhole is used on top of classful qdisc like hfsc it breaks qlen and backlog counters because packets are disappear without notice. In HFSC non-zero qlen while all classes are inactive triggers warning: WARNING: ... at net/sched/sch_hfsc.c:1393 hfsc_dequeue+0xba4/0xe90 [sch_hfsc] and schedules watchdog work endlessly. This patch return __NET_XMIT_BYPASS in addition to NET_XMIT_SUCCESS, this flag tells upper layer: this packet is gone and isn't queued. Signed-off-by: Konstantin Khlebnikov <khlebni...@yandex-team.ru> --- net/sched/sch_blackhole.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/sch_blackhole.c b/net/sched/sch_blackhole.c index c98a61e980ba..9c4c2bb547d7 100644 --- a/net/sched/sch_blackhole.c +++ b/net/sched/sch_blackhole.c @@ -21,7 +21,7 @@ static int blackhole_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { qdisc_drop(skb, sch, to_free); - return NET_XMIT_SUCCESS; + return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;Why do not we use instead : return qdisc_drop(skb, sch, to_free); Although noop_enqueue() seems to use : return NET_XMIT_CN; Oh well.
I suppose "blackhole" should work like "successful" xmit, but counted as drop.
