[RFC PATCH 05/13] net: sched: a dflt qdisc may be used with per cpu stats

[John Fastabend]

Enable dflt qdisc support for per cpu stats before this patch a
dflt qdisc was required to use the global statistics qstats and
bstats.

Signed-off-by: John Fastabend <john.r.fastab...@intel.com>
---
 net/sched/sch_generic.c |   24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index af32418..f8fec81 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -645,18 +645,34 @@ struct Qdisc *qdisc_create_dflt(struct netdev_queue 
*dev_queue,
        struct Qdisc *sch;
 
        if (!try_module_get(ops->owner))
-               goto errout;
+               return NULL;
 
        sch = qdisc_alloc(dev_queue, ops);
        if (IS_ERR(sch))
-               goto errout;
+               return NULL;
        sch->parent = parentid;
 
-       if (!ops->init || ops->init(sch, NULL) == 0)
+       if (!ops->init)
                return sch;
 
-       qdisc_destroy(sch);
+       if (ops->init(sch, NULL))
+               goto errout;
+
+       /* init() may have set percpu flags so init data structures */
+       if (qdisc_is_percpu_stats(sch)) {
+               sch->cpu_bstats =
+                       netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
+               if (!sch->cpu_bstats)
+                       goto errout;
+
+               sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
+               if (!sch->cpu_qstats)
+                       goto errout;
+       }
+
+       return sch;
 errout:
+       qdisc_destroy(sch);
        return NULL;
 }
 EXPORT_SYMBOL(qdisc_create_dflt);