Re: [RFC PATCH 12/13] net: sched: add support for TCQ_F_NOLOCK subqueues to sch_mq

On 16-08-17 12:38 PM, John Fastabend wrote:

The sch_mq qdisc creates a sub-qdisc per tx queue which are then
called independently for enqueue and dequeue operations. However
statistics are aggregated and pushed up to the "master" qdisc.

This patch adds support for any of the sub-qdiscs to be per cpu
statistic qdiscs. To handle this case add a check when calculating
stats and aggregate the per cpu stats if needed.

Also exports __gnet_stats_copy_queue() to use as a helper function.

Signed-off-by: John Fastabend <redacted>
---

[...]

+		if (qdisc_is_percpu_stats(qdisc)) {
+			cpu_bstats = qdisc->cpu_bstats;
+			cpu_qstats = qdisc->cpu_qstats;
+		}
+
+		qlen = qdisc_qlen_sum(qdisc);
+
+		__gnet_stats_copy_basic(NULL, &sch->bstats,
+					cpu_bstats, &qdisc->bstats);
+		__gnet_stats_copy_queue(&sch->qstats,
+					cpu_qstats, &qdisc->qstats, qlen);

And also I forgot to bump this onto the atomic qlen and it is still
using the per cpu counters giving the incorrect qlen total.