Re: [net-next PATCH 05/15] net: sched: a dflt qdisc may be used with per cpu stats
From: Eric Dumazet <hidden>
Date: 2016-08-24 16:30:00
On Tue, 2016-08-23 at 13:24 -0700, John Fastabend wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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 80544c2..910b4d15 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c@@ -646,18 +646,34 @@ 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);
Hmm... apparently we have bug here, added in
6da7c8fcbcbdb50ec ("qdisc: allow setting default queuing discipline")
We do not undo the try_module_get() in case of an error.
I will send a fix.