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/include/net/sch_generic.h b/include/net/sch_generic.h
index e7f4e21..df56760 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -58,14 +58,12 @@
* multiqueue device.
*/
#define TCQ_F_WARN_NONWC (1 << 16)
- int padded;
+ u32 limit;
const struct Qdisc_ops *ops;
struct qdisc_size_table __rcu *stab;
struct list_head list;
u32 handle;
u32 parent;
- atomic_t refcnt;
- struct gnet_stats_rate_est rate_est;
int (*reshape_fail)(struct sk_buff *skb,
struct Qdisc *q);
@@ -76,8 +74,9 @@
*/
struct Qdisc *__parent;
struct netdev_queue *dev_queue;
- struct Qdisc *next_sched;
+ struct gnet_stats_rate_est64 rate_est;
+ struct Qdisc *next_sched;
struct sk_buff *gso_skb;
/*
* For performance sake on SMP, we put highly modified fields at the end
@@ -88,8 +87,10 @@
unsigned int __state;
struct gnet_stats_queue qstats;
struct rcu_head rcu_head;
- spinlock_t busylock;
- u32 limit;
+ int padded;
+ atomic_t refcnt;
+
+ spinlock_t busylock ____cacheline_aligned_in_smp;
};
static inline bool qdisc_is_running(const struct Qdisc *qdisc)