From 76e4cb0d3a583900f844f1704b19b7e8c5df8837 Mon Sep 17 00:00:00 2001 From: Paolo Valente Date: Tue, 5 Mar 2013 08:05:02 +0000 Subject: [PATCH] pkt_sched: sch_qfq: remove a useless invocation of qfq_update_eligible QFQ+ can select for service only 'eligible' aggregates, i.e., aggregates that would have started to be served also in the emulated ideal system. As a consequence, for QFQ+ to be work conserving, at least one of the active aggregates must be eligible when it is time to choose the next aggregate to serve. The set of eligible aggregates is updated through the function qfq_update_eligible(), which does guarantee that, after its invocation, at least one of the active aggregates is eligible. Because of this property, this function is invoked in qfq_deactivate_agg() to guarantee that at least one of the active aggregates is still eligible after an aggregate has been deactivated. In particular, the critical case is when there are other active aggregates, but the aggregate being deactivated happens to be the only one eligible. However, this precaution is not needed for QFQ+ to be work conserving, because update_eligible() is always invoked also at the beginning of qfq_choose_next_agg(). This patch removes the additional invocation of update_eligible() in qfq_deactivate_agg(). Signed-off-by: Paolo Valente Reviewed-by: Fabio Checconi Signed-off-by: David S. Miller --- net/sched/sch_qfq.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c index 6b7ce803d07c..d51852bba01c 100644 --- a/net/sched/sch_qfq.c +++ b/net/sched/sch_qfq.c @@ -1383,8 +1383,6 @@ static void qfq_deactivate_agg(struct qfq_sched *q, struct qfq_aggregate *agg) __set_bit(grp->index, &q->bitmaps[s]); } } - - qfq_update_eligible(q); } static void qfq_qlen_notify(struct Qdisc *sch, unsigned long arg) -- 2.30.2