[RFC PATCH v2 2/4] net: core: use a dynamic_call for pt_prev->func() in RX path

[Edward Cree]

Typically a small number of callees, such as ip[v6]_rcv or packet_rcv,
 will cover most packets.

Signed-off-by: Edward Cree <ec...@solarflare.com>
---
 net/core/dev.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 8e276e0192a1..7b38a33689d8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -146,6 +146,7 @@
 #include <net/udp_tunnel.h>
 #include <linux/net_namespace.h>
 #include <linux/indirect_call_wrapper.h>
+#include <linux/dynamic_call.h>
 
 #include "net-sysfs.h"
 
@@ -1949,6 +1950,9 @@ int dev_forward_skb(struct net_device *dev, struct 
sk_buff *skb)
 }
 EXPORT_SYMBOL_GPL(dev_forward_skb);
 
+DYNAMIC_CALL_4(int, deliver_skb, struct sk_buff *, struct net_device *,
+              struct packet_type *, struct net_device *);
+
 static inline int deliver_skb(struct sk_buff *skb,
                              struct packet_type *pt_prev,
                              struct net_device *orig_dev)
@@ -1956,7 +1960,7 @@ static inline int deliver_skb(struct sk_buff *skb,
        if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
                return -ENOMEM;
        refcount_inc(&skb->users);
-       return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
+       return dynamic_deliver_skb(pt_prev->func, skb, skb->dev, pt_prev, 
orig_dev);
 }
 
 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
@@ -4970,7 +4974,8 @@ static int __netif_receive_skb_one_core(struct sk_buff 
*skb, bool pfmemalloc)
 
        ret = __netif_receive_skb_core(skb, pfmemalloc, &pt_prev);
        if (pt_prev)
-               ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
+               ret = dynamic_deliver_skb(pt_prev->func, skb, skb->dev, pt_prev,
+                                         orig_dev);
        return ret;
 }
 
@@ -5015,7 +5020,8 @@ static inline void __netif_receive_skb_list_ptype(struct 
list_head *head,
                pt_prev->list_func(head, pt_prev, orig_dev);
        else
                list_for_each_entry_safe(skb, next, head, list)
-                       pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
+                       dynamic_deliver_skb(pt_prev->func, skb, skb->dev,
+                                           pt_prev, orig_dev);
 }
 
 static void __netif_receive_skb_list_core(struct list_head *head, bool 
pfmemalloc)