net: sched: optimize class dumps

edumazet · davem330 · commit cb395b201087 · 2017-05-11T21:37:40.000-04:00
In commit 59cc1f6 ("net: sched: convert qdisc linked list to hashtable") we missed the opportunity to considerably speed up tc_dump_tclass_root() if a qdisc handle is provided by user. Instead of iterating all the qdiscs, use qdisc_match_from_root() to directly get the one we look for. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
@@ -1831,6 +1831,12 @@ static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
 	if (!qdisc_dev(root))
 		return 0;
 
+	if (tcm->tcm_parent) {
+		q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
+		if (q && tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
+			return -1;
+		return 0;
+	}
 	hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
 		if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
 			return -1;
