Re: [PATCH 2/2] net: sched: avoid duplicates in qdisc dump

On Tue, Aug 16, 2016 at 2:53 PM, Jiri Kosina [off-list ref] wrote:

From: Jiri Kosina <redacted>

tc_dump_qdisc() performs dumping of the per-device qdiscs in two phases;
first, the "standard" dev->qdisc is being dumped. Second, if there is/are
ingress queue(s), they are being dumped as well.

After conversion of netdevice's qdisc linked-list into hashtable, these
two sets are not in two disjunctive sets/lists any more, but are both
"reachable" directly from netdevice's hashtable. As a consequence, the
"full-depth" dump of the ingress qdiscs results in immediately hitting the
netdevice hashtable again, and duplicating the dump that has already been
performed for dev->qdisc.
What in fact needs to be dumped in case of ingress queue is "just" the
top-level ingress qdisc, as everything else has been dumped already.

Doesn't this mean we can now just remove the ingress case from
tc_dump_qdisc() and simply iterate the whole hash table?