From b362487a3b3524601a60518ae76ffd02a540994b Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Sat, 4 May 2019 11:43:42 -0700 Subject: sch_htb: redefine htb qdisc overlimits In commit 3c75f6ee139d ("net_sched: sch_htb: add per class overlimits counter") we added an overlimits counter for each HTB class which could properly reflect how many times we use up all the bandwidth on each class. However, the overlimits counter in HTB qdisc does not, it is way bigger than the sum of each HTB class. In fact, this qdisc overlimits counter increases when we have no skb to dequeue, which happens more often than we run out of bandwidth. It makes more sense to make this qdisc overlimits counter just be a sum of each HTB class, in case people still get confused. I have verified this patch with one single HTB class, where HTB qdisc counters now always match HTB class counters as expected. Eric suggested we could fold this field into 'direct_pkts' as we only use its 32bit on 64bit CPU, this saves one cache line. Cc: Eric Dumazet Signed-off-by: Cong Wang Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/sch_htb.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index d27d9bc9d010..909370049fca 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -165,7 +165,8 @@ struct htb_sched { /* non shaped skbs; let them go directly thru */ struct qdisc_skb_head direct_queue; - long direct_pkts; + u32 direct_pkts; + u32 overlimits; struct qdisc_watchdog watchdog; @@ -533,8 +534,10 @@ htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff) if (new_mode == cl->cmode) return; - if (new_mode == HTB_CANT_SEND) + if (new_mode == HTB_CANT_SEND) { cl->overlimits++; + q->overlimits++; + } if (cl->prio_activity) { /* not necessary: speed optimization */ if (cl->cmode != HTB_CANT_SEND) @@ -937,7 +940,6 @@ ok: goto ok; } } - qdisc_qstats_overlimit(sch); if (likely(next_event > q->now)) qdisc_watchdog_schedule_ns(&q->watchdog, next_event); else @@ -1048,6 +1050,7 @@ static int htb_dump(struct Qdisc *sch, struct sk_buff *skb) struct nlattr *nest; struct tc_htb_glob gopt; + sch->qstats.overlimits = q->overlimits; /* Its safe to not acquire qdisc lock. As we hold RTNL, * no change can happen on the qdisc parameters. */ -- cgit