Re: [PATCH net-next,v2 05/12] cls_flower: add statistics retrieval infrastructure and use it

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Mon, Nov 19, 2018 at 02:57:05PM +0100, Jiri Pirko wrote:
> Mon, Nov 19, 2018 at 01:15:12AM CET, pablo@netfilter.org wrote:
[...]
> >diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
> >index 7d7aefa5fcd2..7f9a8d5ca945 100644
> >--- a/include/net/pkt_cls.h
> >+++ b/include/net/pkt_cls.h
> >@@ -758,6 +758,12 @@ enum tc_fl_command {
> > 	TC_CLSFLOWER_TMPLT_DESTROY,
> > };
> > 
> >+struct tc_cls_flower_stats {
> >+	u64	pkts;
> >+	u64	bytes;
> >+	u64	lastused;
> >+};
> >+
> > struct tc_cls_flower_offload {
> > 	struct tc_cls_common_offload common;
> > 	enum tc_fl_command command;
> >@@ -765,6 +771,7 @@ struct tc_cls_flower_offload {
> > 	struct flow_rule rule;
> > 	struct tcf_exts *exts;
> > 	u32 classid;
> >+	struct tc_cls_flower_stats stats;
> > };
> > 
> > static inline struct flow_rule *
> >@@ -773,6 +780,14 @@ tc_cls_flower_offload_flow_rule(struct tc_cls_flower_offload *tc_flow_cmd)
> > 	return &tc_flow_cmd->rule;
> > }
> > 
> >+static inline void tc_cls_flower_stats_update(struct tc_cls_flower_offload *cls_flower,
> >+					      u64 pkts, u64 bytes, u64 lastused)
> >+{
> >+	cls_flower->stats.pkts		= pkts;
> >+	cls_flower->stats.bytes		= bytes;
> >+	cls_flower->stats.lastused	= lastused;
> 
> Why do you need to store the values here in struct tc_cls_flower_offload?
> Why don't you just call tcf_exts_stats_update()? Basically,
> tc_cls_flower_stats_update() should be just wrapper around
> tcf_exts_stats_update() so that drivers wouldn't use ->exts directly, as
> you will remove them in follow-up patches, no?

Patch 07/12 stops exposing tc action exts to drivers, so we need a
structure (struct tc_cls_flower_stats) to convey this statistics back
to the cls_flower frontend.