Merge branch 'net-mini_Qdisc'

Jiri Pirko says:

====================
net: core: introduce mini_Qdisc and eliminate usage of tp->q for clsact fastpath

This patchset's main patch is patch number 2. It carries the
description. Patch 1 is just a dependency.

---
v3->v4:
- rebased to be applicable on top of the current net-next
v2->v3:
- Using head change callback to replace miniq pointer every time tp head
  changes. This eliminates one rcu dereference and makes the claim "without
  added overhead" valid.
v1->v2:
- Use dev instead of skb->dev in sch_handle_egress as pointed out by Daniel
- Fixed synchronize_rcu_bh() in mini_qdisc_disable and commented
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 48 insertions, 12 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 5e02f79b2110..7de7656550c2 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1559,6 +1559,8 @@ enum netdev_priv_flags {
  *
  *      @rx_handler:            handler for received packets
  *      @rx_handler_data:       XXX: need comments on this one
+ *      @miniq_ingress:         ingress/clsact qdisc specific data for
+ *                              ingress processing
  *      @ingress_queue:         XXX: need comments on this one
  *      @broadcast:             hw bcast address
  *
@@ -1576,7 +1578,8 @@ enum netdev_priv_flags {
  *      @tx_global_lock:        XXX: need comments on this one
  *
  *      @xps_maps:      XXX: need comments on this one
- *
+ *      @miniq_egress:          clsact qdisc specific data for
+ *                              egress processing
  *      @watchdog_timeo:        Represents the timeout that is used by
  *                              the watchdog (see dev_watchdog())
  *      @watchdog_timer:        List of timers
@@ -1795,7 +1798,7 @@ struct net_device {
         void __rcu              *rx_handler_data;
 
 #ifdef CONFIG_NET_CLS_ACT
-        struct tcf_proto __rcu  *ingress_cl_list;
+        struct mini_Qdisc __rcu *miniq_ingress;
 #endif
         struct netdev_queue __rcu *ingress_queue;
 #ifdef CONFIG_NETFILTER_INGRESS
@@ -1826,7 +1829,7 @@ struct net_device {
         struct xps_dev_maps __rcu *xps_maps;
 #endif
 #ifdef CONFIG_NET_CLS_ACT
-        struct tcf_proto __rcu  *egress_cl_list;
+        struct mini_Qdisc __rcu *miniq_egress;
 #endif
 
         /* These may be needed for future network-power-down code. */
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index d15c40c7bde7..505d4b71975f 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -26,6 +26,8 @@ enum tcf_block_binder_type {
 
 struct tcf_block_ext_info {
         enum tcf_block_binder_type binder_type;
+        tcf_chain_head_change_t *chain_head_change;
+        void *chain_head_change_priv;
 };
 
 struct tcf_block_cb;
@@ -37,12 +39,10 @@ struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 void tcf_chain_put(struct tcf_chain *chain);
 int tcf_block_get(struct tcf_block **p_block,
                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q);
-int tcf_block_get_ext(struct tcf_block **p_block,
-                      struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
                       struct tcf_block_ext_info *ei);
 void tcf_block_put(struct tcf_block *block);
-void tcf_block_put_ext(struct tcf_block *block,
-                       struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
                        struct tcf_block_ext_info *ei);
 
 static inline struct Qdisc *tcf_block_q(struct tcf_block *block)
@@ -82,8 +82,7 @@ int tcf_block_get(struct tcf_block **p_block,
 }
 
 static inline
-int tcf_block_get_ext(struct tcf_block **p_block,
-                      struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
                       struct tcf_block_ext_info *ei)
 {
         return 0;
@@ -94,8 +93,7 @@ static inline void tcf_block_put(struct tcf_block *block)
 }
 
 static inline
-void tcf_block_put_ext(struct tcf_block *block,
-                       struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
                        struct tcf_block_ext_info *ei)
 {
 }
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index c23e938f5b19..c64e62c9450a 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -260,9 +260,12 @@ struct qdisc_skb_cb {
         unsigned char           data[QDISC_CB_PRIV_LEN];
 };
 
+typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
+
 struct tcf_chain {
         struct tcf_proto __rcu *filter_chain;
-        struct tcf_proto __rcu **p_filter_chain;
+        tcf_chain_head_change_t *chain_head_change;
+        void *chain_head_change_priv;
         struct list_head list;
         struct tcf_block *block;
         u32 index; /* chain index */
@@ -901,4 +904,36 @@ static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
         res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
 }
 
+/* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
+ * The fast path only needs to access filter list and to update stats
+ */
+struct mini_Qdisc {
+        struct tcf_proto *filter_list;
+        struct gnet_stats_basic_cpu __percpu *cpu_bstats;
+        struct gnet_stats_queue __percpu *cpu_qstats;
+        struct rcu_head rcu;
+};
+
+static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
+                                                const struct sk_buff *skb)
+{
+        bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
+}
+
+static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
+{
+        this_cpu_inc(miniq->cpu_qstats->drops);
+}
+
+struct mini_Qdisc_pair {
+        struct mini_Qdisc miniq1;
+        struct mini_Qdisc miniq2;
+        struct mini_Qdisc __rcu **p_miniq;
+};
+
+void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
+                          struct tcf_proto *tp_head);
+void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
+                          struct mini_Qdisc __rcu **p_miniq);
+
 #endif