net_sched: add 64bit rate estimators

struct gnet_stats_rate_est contains u32 fields, so the bytes per second
field can wrap at 34360Mbit.

Add a new gnet_stats_rate_est64 structure to get 64bit bps/pps fields,
and switch the kernel to use this structure natively.

This structure is dumped to user space as a new attribute :

TCA_STATS_RATE_EST64

Old tc command will now display the capped bps (to 34360Mbit), instead
of wrapped values, and updated tc command will display correct
information.

Old tc command output, after patch :

eric:~# tc -s -d qd sh dev lo
qdisc pfifo 8001: root refcnt 2 limit 1000p
 Sent 80868245400 bytes 1978837 pkt (dropped 0, overlimits 0 requeues 0)
 rate 34360Mbit 189696pps backlog 0b 0p requeues 0

This patch carefully reorganizes "struct Qdisc" layout to get optimal
performance on SMP.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 1bc210f..71a5688 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -130,7 +130,7 @@
 	psched_time_t		penalized;
 	struct gnet_stats_basic_packed bstats;
 	struct gnet_stats_queue qstats;
-	struct gnet_stats_rate_est rate_est;
+	struct gnet_stats_rate_est64 rate_est;
 	struct tc_cbq_xstats	xstats;
 
 	struct tcf_proto	*filter_list;
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index 759b308..8302717 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -25,7 +25,7 @@
 
 	struct gnet_stats_basic_packed		bstats;
 	struct gnet_stats_queue		qstats;
-	struct gnet_stats_rate_est	rate_est;
+	struct gnet_stats_rate_est64	rate_est;
 	struct list_head		alist;
 	struct Qdisc			*qdisc;
 
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 9facea0..c407561 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -114,7 +114,7 @@
 
 	struct gnet_stats_basic_packed bstats;
 	struct gnet_stats_queue qstats;
-	struct gnet_stats_rate_est rate_est;
+	struct gnet_stats_rate_est64 rate_est;
 	unsigned int	level;		/* class level in hierarchy */
 	struct tcf_proto *filter_list;	/* filter list */
 	unsigned int	filter_cnt;	/* filter count */
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index adaedd7..162fb80 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -78,7 +78,7 @@
 	/* general class parameters */
 	struct gnet_stats_basic_packed bstats;
 	struct gnet_stats_queue qstats;
-	struct gnet_stats_rate_est rate_est;
+	struct gnet_stats_rate_est64 rate_est;
 	struct tc_htb_xstats xstats;	/* our special stats */
 	int refcnt;		/* usage count of this class */
 
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index d51852b..7c195d9 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -138,7 +138,7 @@
 
 	struct gnet_stats_basic_packed bstats;
 	struct gnet_stats_queue qstats;
-	struct gnet_stats_rate_est rate_est;
+	struct gnet_stats_rate_est64 rate_est;
 	struct Qdisc *qdisc;
 	struct list_head alist;		/* Link for active-classes list. */
 	struct qfq_aggregate *agg;	/* Parent aggregate. */