net/sched: Change act_api and act_xxx modules to use IDR

Typically, each TC filter has its own action. All the actions of the
same type are saved in its hash table. But the hash buckets are too
small that it degrades to a list. And the performance is greatly
affected. For example, it takes about 0m11.914s to insert 64K rules.
If we convert the hash table to IDR, it only takes about 0m1.500s.
The improvement is huge.

But please note that the test result is based on previous patch that
cls_flower uses IDR.

Signed-off-by: Chris Mi <chrism@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/act_api.h

@@ -10,12 +10,9 @@
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
-
-struct tcf_hashinfo {
-	struct hlist_head	*htab;
-	unsigned int		hmask;
-	spinlock_t		lock;
-	u32			index;
+struct tcf_idrinfo {
+	spinlock_t	lock;
+	struct idr	action_idr;
 };
 
 struct tc_action_ops;
@@ -25,9 +22,8 @@ struct tc_action {
 	__u32				type; /* for backward compat(TCA_OLD_COMPAT) */
 	__u32				order;
 	struct list_head		list;
-	struct tcf_hashinfo		*hinfo;
+	struct tcf_idrinfo		*idrinfo;
 
-	struct hlist_node		tcfa_head;
 	u32				tcfa_index;
 	int				tcfa_refcnt;
 	int				tcfa_bindcnt;
@@ -44,7 +40,6 @@ struct tc_action {
 	struct tc_cookie	*act_cookie;
 	struct tcf_chain	*goto_chain;
 };
-#define tcf_head	common.tcfa_head
 #define tcf_index	common.tcfa_index
 #define tcf_refcnt	common.tcfa_refcnt
 #define tcf_bindcnt	common.tcfa_bindcnt
@@ -57,27 +52,6 @@ struct tc_action {
 #define tcf_lock	common.tcfa_lock
 #define tcf_rcu		common.tcfa_rcu
 
-static inline unsigned int tcf_hash(u32 index, unsigned int hmask)
-{
-	return index & hmask;
-}
-
-static inline int tcf_hashinfo_init(struct tcf_hashinfo *hf, unsigned int mask)
-{
-	int i;
-
-	spin_lock_init(&hf->lock);
-	hf->index = 0;
-	hf->hmask = mask;
-	hf->htab = kzalloc((mask + 1) * sizeof(struct hlist_head),
-			   GFP_KERNEL);
-	if (!hf->htab)
-		return -ENOMEM;
-	for (i = 0; i < mask + 1; i++)
-		INIT_HLIST_HEAD(&hf->htab[i]);
-	return 0;
-}
-
 /* Update lastuse only if needed, to avoid dirtying a cache line.
  * We use a temp variable to avoid fetching jiffies twice.
  */
@@ -126,53 +100,51 @@ struct tc_action_ops {
 };
 
 struct tc_action_net {
-	struct tcf_hashinfo *hinfo;
+	struct tcf_idrinfo *idrinfo;
 	const struct tc_action_ops *ops;
 };
 
 static inline
 int tc_action_net_init(struct tc_action_net *tn,
-		       const struct tc_action_ops *ops, unsigned int mask)
+		       const struct tc_action_ops *ops)
 {
 	int err = 0;
 
-	tn->hinfo = kmalloc(sizeof(*tn->hinfo), GFP_KERNEL);
-	if (!tn->hinfo)
+	tn->idrinfo = kmalloc(sizeof(*tn->idrinfo), GFP_KERNEL);
+	if (!tn->idrinfo)
 		return -ENOMEM;
 	tn->ops = ops;
-	err = tcf_hashinfo_init(tn->hinfo, mask);
-	if (err)
-		kfree(tn->hinfo);
+	spin_lock_init(&tn->idrinfo->lock);
+	idr_init(&tn->idrinfo->action_idr);
 	return err;
 }
 
-void tcf_hashinfo_destroy(const struct tc_action_ops *ops,
-			  struct tcf_hashinfo *hinfo);
+void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
+			 struct tcf_idrinfo *idrinfo);
 
 static inline void tc_action_net_exit(struct tc_action_net *tn)
 {
-	tcf_hashinfo_destroy(tn->ops, tn->hinfo);
-	kfree(tn->hinfo);
+	tcf_idrinfo_destroy(tn->ops, tn->idrinfo);
+	kfree(tn->idrinfo);
 }
 
 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 		       struct netlink_callback *cb, int type,
 		       const struct tc_action_ops *ops);
-int tcf_hash_search(struct tc_action_net *tn, struct tc_action **a, u32 index);
-u32 tcf_hash_new_index(struct tc_action_net *tn);
-bool tcf_hash_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
+int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index);
+bool tcf_idr_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
 		    int bind);
-int tcf_hash_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
-		    struct tc_action **a, const struct tc_action_ops *ops, int bind,
-		    bool cpustats);
-void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est);
-void tcf_hash_insert(struct tc_action_net *tn, struct tc_action *a);
+int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
+		   struct tc_action **a, const struct tc_action_ops *ops,
+		   int bind, bool cpustats);
+void tcf_idr_cleanup(struct tc_action *a, struct nlattr *est);
+void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a);
 
-int __tcf_hash_release(struct tc_action *a, bool bind, bool strict);
+int __tcf_idr_release(struct tc_action *a, bool bind, bool strict);
 
-static inline int tcf_hash_release(struct tc_action *a, bool bind)
+static inline int tcf_idr_release(struct tc_action *a, bool bind)
 {
-	return __tcf_hash_release(a, bind, false);
+	return __tcf_idr_release(a, bind, false);
 }
 
 int tcf_register_action(struct tc_action_ops *a, struct pernet_operations *ops);